Signing a contract don't mean a thing to them

I had a contract with them and payment was paid on time and in full. Full period of the contract was paid but still they deducted the premium and I reversed it now they say I owe them. R428.44. but I phone few months earlier to enquire about when will the contract expire, and I was told April. Buy they deducted on 02 May and I reversed it on 04 May. I received a call from Margaret that says I'm owing, I told her I m not owing. She said they change my contract to monthly basis without informing me. I told her that the only contract I agree on was the one that I signed and payed for, they were supposed to inform or ask me if I want month to month. Now I received an email and a call today but my bettrie died while we on call. Their contact: ********** 006/0 , ********** 222, email: **********

Vehicle:NUF12254