Over charge & incorrect disconnect

I have been a customer for over 7 years, never skipped a payment. Multichoice upgraded their systems in Aug & everything went pear shaped. I am on price lock R749, on 19 Sept I got a disconnection SMS & they did disconnect my service, stating arrears of R1100. Livid as I was, called in only to find out they made a mistake. Then, 20 Sept they debit R1100 instead of R749. A week later I was disconnected again!! The consultant sent a mail to price lock, believe it or not they don't have an inbound to answer customer complaints. No one has responded to the email, I followed up 2 days ago, no answer. I am very dissatisfied, I've been inconvenienced highly & this is definitely not Treating customers fairly. I'd like to be refunded for the overcharge and an apology letter for such bad service.