Sony Xperia E4 (Pathetic service)

on the ***5 my Fiance bought a phone for cash from the saleman Martin as he was in that area but he is from limpopo and I live on the east rand. The phone switched off and even though my fiance asked him he said the phone was right. When I received the phone that evening it was faulty and just rebooted on its own at random times it was then placed back in the box.On the ***5 the phone was returned to vodacom and we were advised to wait 7 days as per policy and procedure as the phone has to first be checked by their technicians and that we cannot get the cash back and they provided me with a courtesy phone. After numorous phone calls to other staff and Hebron they advised that they have the phone and that they want to post it. We then advised them if they post it how would they get the courtesy phone their answer was that we should post it. In the first place according to me the phone was sold broken, secondly why must one wait so long if it states that the phone should be returned withing a 7 day period, thirdly why should I bare the costs of posting/driving till there. It is 9 days now called Hebron again 2day he said he'l try to arrange and now his unavailable