What voice is that recording speaking with? Check your Asterisk logs - does it indicate that the call is being received and rejected? I ask, because you may (at least temporarily) want to set "Allow anonymous SIP calls" to Yes under the General Settings tab within FreePBX.

Before you go changing any settings, do check your Asterisk log just after making a call to your number (with or without your PAP2T on). If the call is properly hitting your Asterisk system, the logs will help you troubleshoot.