Yet another month of poor service at dstv !!!

After changing my package at dstv several months ago, dstv still debits the incorrect amount from my account. Each month i need to call in to query this and after spending a minimum of 20min on a call, they agree to do a refund. This month again, i sit with the same problem...and what does dstv do...they disconnect me!!!! When asking ro speak to a supervisor, they refuse to put me through....terrible service!!!!! Tired of this!!!!