Vodacom telesales is *****!!!!

Telesales of vodacom sold an contract to me when i recieved the phone it was an OBF and i took it to my neerest store telesales contacted me again and asked if i were happy i said that i was very unhappy and that the phone was send back to them i do not want the contract. Today i recieved an final demand for payments!!!! This is stupid and *****!!!!