Register Failed sim card

It is will great disappointment that I am writing this. I am so hurt. I lost my phone at the beginning of this month, and I went to MTN in Fourways to do a sim swap on the 7th of this month. I was told that the sim swap should be complete in 24 hours, I waited and when I switched my phone on it said Register failed, I went back to MTN on the 9th and I was told that they have submitted the query to whoever and I will get a call, which I never did. I went back again on the 13th, still the same thing, They keep telling me they will call me back but nothing, since then I have been going to MTN everyday. They are always singing the same song, the person who stole my phone is declining the sim swap, I dont want to hear problems, I want solutions. If they cant do something to make that person stop declining my sim swap who else can, Vodacom. Like I am so angry at the people there, sometimes they would just stand there and ignore me. I am pained by this because I paid for the sim swap and its a contract which I am paying 600 for it every month, my phone is gone so atleast I need to have my sim card so that I am not paying for nothing but no, they are so insensitive and ***********. I am missing important phone calls and its been 3 weeks now, I mean 3 weeks!!!! MTN has to do something or else give me my sim swap money back since there is no sim swap done. Im so disappointed in MTN.