poor poor service from Game store

good morning very bad service went to a game store in Johannesburg for a item on special they had no stock but promised me as soon as they got stock would let me now. they then sold me a second hand unit when i returned the item were not very helpful. i then contacted the customer service department they. promised to investigate the matter and come back to me .no response. i contacted them the second time they had all my details and still no luck