MTN very bad service

I got month to month contract with Mtn, on the 4th of February I paid via EFT they then disconnected my number because they said money never reflected on the system. On the 8th I spoke to Zanele I sent proof of payment to her email my number was only reconnected on 15th of February. On the 22nd of February I received messages saying I must pay R351 when I call to find out I spoke to Ayanda whom told me I must pay R351 to keep my number working and she doesn't know when the payment I made will be verified. When I asked to speak to someone who can clarify it for she was very rude and said there's no way she can help me. If MTN can't provide me with services I paid for they must just refund my money. Because they failing to tell me how long does payment be verified after proof of payment is made I'm so disappointed in their service