MTN (MOST TROUBLESOME NETWORK)

A while ago I changed banks. I tried to call and email MTN but no one answered to any of my reach outs so I could not update my banking details to MTN's fault. I resorted to paying my bills via the MTN app. Each payment being successful. After doing this for 3 months you have deactivated my accounts saying that I am in arrears and the reason is I must print out these POPs and send them to one of your stores. Wasting my time. PLEASE TELL ME WHY I AM SUFFERING BECAUSE OF YOUR INCOMPETANCIES????