African Bank calls wrong number and calls me stupi

I have asked previously that African bank can remove my number from there systems because they keep on calling me and asking for somebody I DO NOT KNOW!!! for more than a year now and easily put I am fed up with it how hard can it be to remove my number from an account that does not belong to me?Best of all I have an account at African Bank with MY NUMBER so how can 2 accounts with different account holders have the same number? but today a lady called and asked again to speak to this man that is owing african bank and I am a lady so clearly I am not the person she is looking for I asked her do I sound like this person you are looking for she told me I am stupid and when I asked her what her name was she dropped the phone in my ear I would like to know who this lady is and were does african bank find these people to phone customers that does not have any phone etiquette or do they just hire any un educated person of the street, I work for a large company that owns a group of companies and if any other person calls anybody customer or positional customer stupid they will be dealt with accordingly or does african bank simply dont care?