Phone network disconnects

I received my new phone about 6 months ago and ever since the new phone I had problems first the guy couldn't get my number on the contract which left me and my husband almost a month uncontactable ...I realized my phone kept on losing connection and went into the century city branch the technician checked and recommended a Sim swop it was done it didn't work...I then went numerous times to Capegate Branch where the technician also recommended a Sim swop I told him it was done it didn't work he then did settings and stuff on my phone and also confirmed there has been a problem with quite a few clients and after the Sim swop it worked well mine didn't work he now attempted probably four times for the head office to call me no call no nothing and my phone is messing me around to the fact that my husband was in an accident nobody could get hold of me telkom I can't pay for a phone which is nor providing me the service I'm paying for