MTN Useless

I received a phone call from MTN (I am not sure it was really them) informing me that a SIM swop was attemted on my phone. Being worried I tried to phone them on 135 but on this number no person can be contacted. Number 180 do not work at all. I send e-mails to Customer care who rep**** that they will respond within 8 hours to no avail. The e-mail to the ***** department also had no response. In the mean time I am still worried and MTN sucks.