Dropped calls and slow internet

My family and I have been experiencing dropped calls in the Durban area and especially poor data signal in Amanzimtoti. Re calls there is often interference and one has to call again. Or when dialling the call just disconnecta. One has to dial over and over again to get a ring tone. Internet is especially bad. Very slow internet and sometimes no signal at all. There is often barely a signal. This has been experienced by family members and friends in the area. We are not paying for a sub - standard service . I have emailed and phoned Vodacom re the poor coverage. Not even received a reply. Also contacted Twitter contact no success. Vodacom email complaint service is not operational