Payment goes "missing" usin MTN App

I made a payment using the MTN App. I received confirmation that the payment was successful. A few days later my line was suspended because the payment did not reflect on MTN and was called a missing payment. I don't understand how this happens, if you want customers to use your app and payments goes "missing" . I have been in contact with customer care but they don't care at all. Can't wait for my contract to end so I can move. Account nr BA***