DSTV WORST SERVICE WITH REGARDS TO ACCOUNTING

I have been having a query with DSTV for debiting my account incorrectly. They owe me almost 400 since December, I've been calling every week to get the problem sorted. Ive been speaking to supervisors that promised me it would have been resolved already. I spoke to Tshepo a supervisor on the 28th of December to get it resolved. They giving me a bad credit score because of this. My one account with them is in credit and the other one in a debit. Up until today no one can resolve the dispute to load the money from 1 account to another account. I spoke to Tshepo, Naomi, Tsolo, Shanice, etc. Who else must i speak to to get my own money back they earning interest on?