Asterisk paid support required

Good Day All,

We are looking to get support to solve one of our problem in asterisk.

Problem: 2,3 Calls daily hanged in asterisk and when it disconnected it comes with high duration more than 2 and 5 hrs. Which made customer balance in negative. We have developed our own billing system and we already using the following extensions to limit the call duration.

[prepaid]
exten => _x.,1,Set(UserN=${CALLERID})
exten => _x.,2,Set(CalledNum=${EXTEN})
exten => _x.,3,Set(Stime=${DATETIME})
exten => _x.,4,Set(CID=${CALLERID})
exten => _x.,5,Set(HCA=${HANGUPCAUSE})
exten => _x.,6,Set(Cun=${UNIQUEID})
exten => _x.,7,AGI(routing.pl)
exten => _x.,8,Set(TIMEOUT(absolute)=${TMO})
exten => _x.,9,Dial(SIP/${CNUM}@${CAIP})
exten => h,1,DeadAGI(stop.pl)

Here us MySQL CDR which show billsec 5209 sec which is totally wrong the customer dialed the number but it was not connected.

Please suggest us if the problem can solve, we are ready to pay for this solutions.

Thank You
Aqbal Ahmad
MSN / Email : support@qualityfone.com