No signal

Upgraded 3-4 months ago to Samsung s6 phones. Expensive contracts. Not able to make or receive calls or sms. No signal in several areas around Jhb. Vodashop say nothing wrong. Vodacom call centre say nothing wrong. Several calls logged. No assistance. Pay close on R5000 per month for an electronic clock and contact register only. Have been cut off from the outside world and nobody cares because they get their money. We get sms from vodacom that they were unable to contact us re the problem. That is the problem. Our phones does not work. Signal break up or cut off. Call centre agents except for 1 are not even interested to try. Shop in Westgate just shrug their shoulders. The next step after this will have to be legal. We cannot pay for a non existant service. Not to mention the inconvenience.