Builders sell equipment with no after sales support on v-homes security systems

I bought a vodacom v-homes from builders, which stopped working for 3 months as a result of vodacom not knowing how their non vodacom customers should pay for the subscription. Builders has no knowledge of the products they are sell nor do they have any after sales support for equipment sold by them... They do not accept responsibility for their lack of knowledge nor can they assist or take back the product.