MTN Insurance claim is a total waste

I’m appalled by the service I got from MTN King Williams Town, I lost my phone on 10 January 2020 in a bus from Joburg, when I went to MTN store in King Williams Town they gave a runaround and told me to contact the customer care. I phoned the customer care and the lady who was assisting me told me that the IMEI number I provided didn’t match with the one they have on the system. I contacted the MTN insurance services where I was told that the IMEI I provided was the one they had in their system but there’s nothing they can do unless I get phone blacklisted by MTN. I’d like this matter to be resolved, because I won’t be in Johannesburg anytime soon so I can’t get the box. I really need this phone as I use it for my business now I’m stuck with no phone. I didn’t know that MTN could do me dirty like this after I’ve never missed one payment for their phone and insurance.