Mtn doesn't care

I've been receiving smses about OTPs and orders being created for me and when I contacted the customer care line I was told an upgrade on my contract was done at some Mtn store. When I ask which store and by whom was the upgrade done I cannot get answers from Mtn. I tried their Twitter account to report this and they keep making false promises. To date no one has contacted me and this is also my 2nd complaint on this platform. I don't know where to turn to anymore.