overcharges

i have two decoders in two of my houses, the old one at R199 subscription and the HD is R315.in late December i called multichoice to ask about the downgrade on teh HD Decoder as i will be in and out of house in January ,downgrading to R99.After it was done i received an invoice in End of January saying my February invoice is R597.<br> this dint make sense as i expected to pay a total R298. i paid the requested total with the aim of resolving the matter later.after calling an being on the line for over an hour(calling with cellphone) i still didnt get help and explanation.<br> i have requested that since i paid more money ,the R99 decoder be upgraded to R315 but this hasn't happened, even though the call center agents keep on saying 'the channels are open on their side'<br> surely after paying this exorbitant money i deserve help?