a2billing expert for multiple tasks - repost

We need someone with good knowledge about a2billing, freepbx, asterisk and linux and with a lot of experience. This time we need to fix an issue, but we will work with you for new things pending to do, like configuring fail-over, multiple outgoing trunks, etc,. so we are looking a long-term tech / team. At the moment, we need to fix an issue with outgoing calls with a2billing, seems that there's any problem in a new elastix box. The issue is: Freepbx extensions dial outgoing numbers and get mesage "please enter complete pin number". After entering the a2billing PIN number (we want to avoid this, already configured the accountcode in every extension) we get a "number currently unavailable". The CDR shown in freepbx shows "answered (twice)" but the provider didn't get anything, so call didn't get out from our box. Seems that this is hapenning most of the times. This is the part of the log I see trying to make the call. Plz check attached txt log file.