Horrible service-MTN

I called MTN to request an upgrade, I was due for it earlier this year but did not take it as I did not need a new phone at the time, I communicated that I’d take the upgrade when I was ready to! I have sent an email as well, a lady called me back and said they cannot find my details on the system! It seems as though my contract was cancelled or my details were cancelled! She said she’d get back to me, still hasn’t! I’ve sent countless emails to follow up but no response! I urgently need to upgrade as my current phone has ink all over the screen and I therefore cannot use it! How do my details get wiped off or my contact cancelled without my acknowledgment!!!!