Poor service

MTN has bad costumer service ever! In 2021 I took out data simcard contract with one of their agents "Mondo" & after few days a canceled as the simcard was not working in my area.Last year i pulled out my credit report only to find out that I'm in arrears of R145 owing to mtn,since then I've been trying to contact them, when I call their customer care a fail security checks even when I give my correct home address after they asked. I've sent in million emails they don't respond, today I'm in arrears of R365 it keeps accumulating & it is badly affecting my credit score. I tried to contact their legal department (Called and flooded their inbox with Emails) even today nothing has happened!