DSTV Price Lock payment queries

I would like to log a complaint about DSTV, where I'm charged more and more every month, from R700 to R926, and they owe me credit. Now it's another story. They give me kibds of amounts, and give excuses, as to why i must pay that amounts. Which does not make sense. I am on price lock and there will be no price increase, now they want to charge me extra R100 for extraview, but the R100 was included in the price lock package. With no extra charges. I have proof where i received a email of how much i must pay. It shows R649.