Kindness Gone Sideways

A nice man at the local store assisted my parents in lowering their costs by switching from cable to streaming; however, the cable was never turned off so they are being asked to pay for both.  My mom has spoken with 6 different people to get the cable charge removed but instead ATT turned off their internet and phone.  My parents pay their bills when they are honest and fair but now they are being punished for trusting ATT to do the right thing.  Help.