Not happy with the service

I'm sick and tired of the service that I receive from multichoice last month I had a problem with them and the query was resolved and my account was credited with R235 today I received an sms stating that I need to pay R1200 but I only took price lock for Compact which cost R685 and when I ask the consultant he said I have 2 decoders with them and I'm asking who reconnected the other one n he's failing to answer that last month I had a credit of R235 and I check the breakdown it's not there so I'm really not happy maybe I will be at peace when I cancel their contract cause I won't be able to phone them every month and the guy that I spk with said this month I will pay R511 and my query was resolved cause I reported them to Hello peter