calls always failing

My number is *** and I ported to CellC approximately 15months or so when I took out their contract.I am sorry I changed to this network because the amount of times my calls drop,gets cut off,is ended before I even connected is astounding.I have complained to cell c in the past and they asssured me that they were upgrading all the infrastructure and calling would be a pleasurable experience going forward.Well time is moving on and the problems are still a daily occurrence.I live in the bothasig area and many of my neighbours have the similar complaints cellc.So there is definitely a problem with your network.Sometime your network tells me my no doesnt exist when I dail my cell so clearly there is big problems.I work alone from home and I am dependant on the mobile for my all my clients to contact me.Please,please,please do something to make these problems go away or I am afraid I wont be renewing anything when this contract is up