MTN failing and going backwards

On Saturday 30 June I payed my MTN account and received a sms stating that you received my payment yet today Monday 2 July you send me a sms again for overdue account. When I spoke to the customer service department they have no confirmation on receiving payment and some how my account is haywire needing to go through a lengthy time consuming verification process and yes I've used my security details now from you started this and have never changed any details in the last 8 years. What is going on in your company as not just is everything going backwards but failing drastically including your signal strengths?