First open at ticket with ACC and insist that they do some intrusive testing. If they do non intrusive testing and just monitor the circuit they won't see the errors that are headed to you, just errors headed to them. An intrusive test will loop the smart jack and they should then see errors headed back to them.
If this happens often I can't stress how important it is to keep detailed records of your trouble tickets. If you can get 3 tickets withing a 30 day period you can ask them to open a chronic ticket which will usually get some attention.
They are probably going to tell you they found a bad pair and will move you to the next pair so that your bad pair will eventually become someone else's bad pair. --
I do not, have not, and will not work for AT&T/Comcast/Verizon/Charter or similar sized company.