Sim swap

There is nothing frustrating as loosing your phone and you call the call centre and they say you are failing there questions. I have used my number for years and I will loose business in the line of work I do, how am I suppose to know when was the first time I obtained my number and price plans I don't work for MTN what I know I load airtime. With all the info I am giving they dont want use. And now I must go to police station to say I lost my phone and send it to MTN. But 2015 changing to a micro sim card it was done with no problem. Now I have to suffer like this cause I am a prepaid customer. Person is frustrated my phone was ****** and now buy MTN and the first person I spoke even refused to black list my lost phone cos I call for sim swap not to black list a phone, this is really bull ...