Change my surname!!

Good day. I have tried a letter from home affairs stipulating that I would like to change my name on my bank account. Here is the thing, my ID all the years whether I was married or not, says Alexander. You changed my surname with a written marriage certificate. My husband is dead. I don't want his surname any longer. I want my name changed to Alexander on my internet and my bank card and my life with FNB please. I also don't want my cheque account any longer and want to downsize back to a savings account. Now for the last time, can someone assist me. Get my name changed. Get my stuff sorted back to Alexander. Come one FNB you better than you acting to many of us at this point.