Day light ******s

I have been with MTN for nearly 20 years if it is not above. The past few months is been hell, They started to suspended my lines stating that I have missed payment in April. I've sent through bank statements showing that the payment was made with no luck. Its been 2 months my lines being suspended and listed as grey when I'm trying to login in their app, which means I am blocked. I have been making my regular monthly payments but my lines are still suspended.