Bad service from Multichoice

Am writing to express my deep concern and disappointment with the issue of Multiplechoice handing my account to MBD attoneys, I odered internet router for 50GB on January but i then received the router for 144GB i call them i didnt get any assistence via telephone i then decided to drive to Randburg i returned the router for 144GB and i came back with the one for 50GB and obviours the account number changed. But now am receiving calls from MBD everyday telling me to make the payment on the router account that i have returned back to Multiple choice router number (***) My DSTV client number (***5) Please help resolve this issue as soon as possible because it is affecting my credit score.