Erraitc cellphone service

From about April this year ,we've had very erratic sercvice from vodacom.At least 2 to 3 times a day there is no internet connection ,no service,emergency calls only etc.Sometimes its for 2 to 3 days without any service.Like i said ,it been ongoing for the past 4 to 5 months now and it is not being sorted.As far as my understanding go,me and Vodacom has an bunding agreement ,they provide the service and i pay them.At this stage Vodacom is in breech of contract ,i do not recieve the service i am paying for .I have a good mind to cancel all of my ,and my wife's contracts whether they like it or not