Specific mobilecall not connecting to my calling card number

my calling card access number worked very well but one of mobile caller couldnot connect to my access number with his mobile number,Changed his provider but same issues provider not helping .
Any one any idea about this ?
looks like his calls bloking linux switch ,
please help

This appears to be a support request, so it is on the wrong forum. However, there is far too little information to understand what your problem is.

It might be worth noting that a Asterisk is a PBX toolkit, not a turnkey PBX. Even if you are using FreePBX (in which case you are on the wrong board) any PBX needs configuring.