On air is a nightmare and not transparent

I agreed to take a deal of DSTV explorer with On air in the beginning of Febuary On monthly installment for 24 months, the explorer was delivered and installation was done.My agreement with the agent was that they would debt R198 on the 5th of every month .so as per usual I go and pay for my monthly payment which is R409 .To my suprise Im now charged R582 and on the Im yet to pay another R198..This were I get lost ..the agent did not say anything about additional cost that im now pay for recording and rewinding ext..so I've been trying to contact their contact Centre and the only thing you get is the machine and they put you on hold until you run out of airtime...I want to cancel the whole contract as Im now paying plus minus R800 for DSTV and this is too much