MTN frustration

I had a call from MTN to say I could get an upgrade, as I could not really understand what was being said, I told her that I would go into a store. After a few days I went into MTN Constantia, the lady told me that I needed to answer various security questions which I did. Just so that you are aware I have been with MTN for about 28 years,.....it was when cell phones came out I got a cellphone from Nashua with a contract from MTN. I have had the same number all the time and they been debiting the same Absa Bank account all this time as well. They are now insistant that the bank account is in my husbands name as well, (he passed away in February) I repeated to them a thousand times that it was a Private Bank account in my name ONLY. Eventually I asked my Private Banker to give me a letter stating this, which she did. I took it back to MTN Constantia and thought this would solve the problem,...not a chance, they then tried my credit card and so it went, he took a copy of the letter and said he would speak to someone. This morning I had a message from the person who was now dealing with my problem! suggesting that he and I go to Absa Bank tomorrow and open another account so that one can be registered with MTN. There are no words to describe the absolute frustration I am having with MTN,... who I have been with for all these years and had my debit order taken off my Absa Private bank account regularly without any fault. They make the excuse of ***** but surely they can check an account and see how it has been managed all these years. Has anyone else had this problem and if so how was it sorted out.