Payment disappears and MTN confirms and then denies receipt!!!

I had a horrible experience with MTN again. I made payment of my monthly fee via EFT and received payment receipt and confirmation from MTN on Monday the 30th April. This morning, I receive a text from MTN saying that the amount is not paid and is still outstanding, after they had confirmed receipt. I called the call center through the contract line as (083 123 does not work) and I was told that the text was probably a mistake generated too late????. the agent (Pumzile Masondo) then assisted me by checking for the payment which she said she could not find. I then proceeded to send her the proof of payment with the supporting texts from MTN. She then raised this with the accounts area and said I will get "feedback" in 2 - 24 hours! I asked if I could speak to accounts as I am clearly quite concerned that the money has invariably DISAPPEARED even though she checked that the right banking details and reference was used. she responded saying that this area does not take calls and that I need to wait...over and above this, I MUST CALL BACK as they will not notify me if it has been corrected or not!! This is a terrible experience and certainly in breach of the Consumer protection act. I would like a response from MTN today with confirmation that I have not been negatively impacted as a result of their maladministration.