Useless mtn

I app**** online for a data simcard March 2020 before lockdown, in less then 10min I received a call from mtn, we went through all the procedures. 2 weeks after the application I received the simcard it was just the simcard no number with it only puk number and pin number. The courier guy told me in 24hours the simcard will be active, after 24hours the simcard was not active. I tried calling customer care no answer, I went on their website for a email address, I have sent them a numerous of emails only received automated replies, I googled numbers which I can call still no answer from mtn side. After 4months with no luck I received sms, emails from mtn saying I must make payment for contract, I checked again and the simcard was still not active, the started sending me invoices, I rep**** on the emails so that I can cancel the contract they just didn't reply on any of my emails. I went to the branch for assistance, they gave me a number I must call for cancelation but still no luck. They have hand me over n css called me telling me I must make a payment of R2500, I told them the simcard never worked, they said they will investigate and come back to me its been 3months they haven't came back to me.