Not registered on network error

in mid Jan 2015 I upgraded from a blackberry Z10. This phone was a nightmare. Hence I decided to upgrade early.<br> <br> I upgraded to Samsung S5. I am now having trouble with either the phone to network. the phone loses connection with the provider. all my calls go to voicemail without my knowledge. When I attempt to dial out then I pick up the error message. I then have to reboot the phone. <br> <br> the inconvenience is massive. I logged a call with Cell C customer service, I was told that there were network problems but I must take my phone in for a check up at the store. I told them that the error is intermittent. I may not get this error for a week at times. furthermore, they say that they can loan me a unit but can not guarantee that it would be a similar unit. <br> <br> Does anyone know of the inconvenience on having social, business contacts stored and the disruptive nature of not having this as easy as we normally do ?<br> <br> I entered into a 2year contract. Cell can not provide the basic service without interruptions. that is, making and receiving calls. <br> <br> Surely, Cell C is in breach of the contract, they can not provide the basic service. Why should I inconvenience myself ?