Bad business service

I made once off payment arrangement with SABC to pay my TV licence. Now they debit my account without arranging with me. They don't even say anything when they are going to debit. In addition, SABC debit more than what the TV licence cost per annum.

I am not happy about the whole thing and i want it to stop. I don't want SABC to debit my account anymore. From now i want to deposit money for TV licence on their account not the other way round. Please help me.