diff --git a/sessionmanager/sessiondelegate.go b/sessionmanager/sessiondelegate.go
index 3cb6d43cd..9a65c3e62 100644
--- a/sessionmanager/sessiondelegate.go
+++ b/sessionmanager/sessiondelegate.go
@@ -51,7 +51,7 @@ type SessionDelegate interface {
 type DirectSessionDelegate byte
 
 func (dsd *DirectSessionDelegate) OnHeartBeat(ev Event) {
-	log.Print("direct hearbeat")
+	log.Print("♥")
 }
 
 func (dsd *DirectSessionDelegate) OnChannelAnswer(ev Event, s *Session) {
@@ -63,16 +63,35 @@ func (dsd *DirectSessionDelegate) OnChannelHangupComplete(ev Event, s *Session)
 	// put credit back	
 	start := time.Now()
 	end := lastCC.Timespans[len(lastCC.Timespans)-1].TimeEnd
-	cost := 0
-	seconds := 0
-	for _, ts := range lastCC.Timespans {
-		if ts.TimeEnd > start {
-			sec := ts.TimeEnd.Sub(start)
-			if ts.Interval.BillingUnit > 0 {
-				cost = (sec / ts.Interval.BillingUnit) * ts.Interval.Price
-			} else {
-				cost = sec * ts.Interval.Price
+	refoundDuration := end.Sub(start).Seconds()
+	cost := 0.0
+	seconds := 0.0
+	log.Printf("Refund duration: %v", refoundDuration)
+	for i := len(lastCC.Timespans) - 1; i >= 0; i-- {
+		ts := lastCC.Timespans[i]
+		tsDuration := ts.GetDuration().Seconds()
+		if refoundDuration <= tsDuration {
+			// find procentage
+			procentage := (refoundDuration * 100) / tsDuration
+			tmpCost := (procentage * ts.Cost) / 100
+			ts.Cost -= tmpCost
+			cost += tmpCost
+			if ts.MinuteInfo != nil {
+				// DestinationPrefix and Price take from lastCC and above caclulus
+				seconds += (procentage * ts.MinuteInfo.Quantity) / 100
 			}
+			// set the end time to now
+			ts.TimeEnd = start
+			break // do not go to other timespans
+		} else {
+			cost += ts.Cost
+			if ts.MinuteInfo != nil {
+				seconds += ts.MinuteInfo.Quantity
+			}
+			// remove the timestamp entirely
+			lastCC.Timespans = lastCC.Timespans[:i]
+			// continue to the next timespan with what is left to refound
+			refoundDuration -= tsDuration
 		}
 	}
 	if cost > 0 {
@@ -82,6 +101,7 @@ func (dsd *DirectSessionDelegate) OnChannelHangupComplete(ev Event, s *Session)
 			DestinationPrefix: lastCC.DestinationPrefix,
 			Amount:            -cost,
 		}
+		cd.SetStorageGetter(storageGetter)
 		cd.DebitCents()
 	}
 	if seconds > 0 {
@@ -91,9 +111,11 @@ func (dsd *DirectSessionDelegate) OnChannelHangupComplete(ev Event, s *Session)
 			DestinationPrefix: lastCC.DestinationPrefix,
 			Amount:            -seconds,
 		}
+		cd.SetStorageGetter(storageGetter)
 		cd.DebitSeconds()
 	}
-	log.Print("Rambursed %v cents, %v seconds")
+	lastCC.Cost -= cost
+	log.Printf("Rambursed %v cents, %v seconds", cost, seconds)
 }
 
 func (dsd *DirectSessionDelegate) LoopAction(s *Session, cd *timespans.CallDescriptor) {
diff --git a/timespans/calldesc.go b/timespans/calldesc.go
index ed2db05c5..3022aa973 100644
--- a/timespans/calldesc.go
+++ b/timespans/calldesc.go
@@ -211,7 +211,7 @@ func (cd *CallDescriptor) GetCost() (*CallCost, error) {
 		if i == 0 && ts.MinuteInfo == nil && ts.Interval != nil {
 			connectionFee = ts.Interval.ConnectFee
 		}
-		cost += ts.GetCost(cd)
+		cost += ts.getCost(cd)
 	}
 	cc := &CallCost{TOR: cd.TOR,
 		CstmId:            cd.CstmId,
@@ -236,7 +236,7 @@ func (cd *CallDescriptor) getPresentSecondCost() (cost float64, err error) {
 	timespans := cd.splitTimeSpan(ts)
 
 	if len(timespans) > 0 {
-		cost = round(timespans[0].GetCost(cd), 3)
+		cost = round(timespans[0].getCost(cd), 3)
 	}
 	return
 }
@@ -278,7 +278,7 @@ func (cd *CallDescriptor) GetMaxSessionTime() (seconds float64, err error) {
 			if i == 0 && ts.MinuteInfo == nil && ts.Interval != nil {
 				cost += ts.Interval.ConnectFee
 			}
-			cost += ts.GetCost(cd)
+			cost += ts.getCost(cd)
 		}
 		if cost < availableCredit {
 			return maxSessionSeconds, nil
diff --git a/timespans/timespans.go b/timespans/timespans.go
index 14366533f..08fa774a0 100644
--- a/timespans/timespans.go
+++ b/timespans/timespans.go
@@ -29,6 +29,7 @@ A unit in which a call will be split that has a specific price related interval
 */
 type TimeSpan struct {
 	TimeStart, TimeEnd time.Time
+	Cost               float64
 	ActivationPeriod   *ActivationPeriod
 	Interval           *Interval
 	MinuteInfo         *MinuteInfo
@@ -48,10 +49,10 @@ func (ts *TimeSpan) GetDuration() time.Duration {
 	return ts.TimeEnd.Sub(ts.TimeStart)
 }
 
-/*
-Returns the cost of the timespan according to the relevant cost interval.
-*/
-func (ts *TimeSpan) GetCost(cd *CallDescriptor) (cost float64) {
+// Returns the cost of the timespan according to the relevant cost interval.
+// It also sets the Cost field of this timespan (used for refound on session
+// manager debit loop where the cost cannot be recalculated)
+func (ts *TimeSpan) getCost(cd *CallDescriptor) (cost float64) {
 	if ts.MinuteInfo != nil {
 		return ts.GetDuration().Seconds() * ts.MinuteInfo.Price
 	}
@@ -70,6 +71,7 @@ func (ts *TimeSpan) GetCost(cd *CallDescriptor) (cost float64) {
 		}
 		userBudget.mux.RUnlock()
 	}
+	ts.Cost = cost
 	return
 }