rood and underming manager

i bought tablet-vodafone-sma worth R1999.00 and it was too very slow on operating on internet and other networks. i bought it on the 20/03/2015 and because of i was not happy with it, i went back to the store to return it so that i can get a better one. the guys working in the store sent me to the manager who should assist me. he started by beeing rood to me saying he is busy and he cant help me. i told him that i just want to return the tablet because it is so very slow. he said he wont refund my money back unless if the tablet was damaged or broken. then he said it will be better if i sell it back to them but the money it will be lower than the money i used when buying it. then i told them that im going to report this matter and he said even if i come with my lawyers he wont give me back my money. the receipt of the tablet shows that goods returned within 6 months of purchase can be refunded at the purchase price, but the manager refused to give back my money on something that doesnt have 5 day of purchase. i want my money back and im still going to take this matter even further till this thing of robing peoples money and undermining people is completly over