Shoes that are supposed to be The Elite running shoes, but kills and injures feet more than anything.

I bought shoes at MR Price Sport Tygervalley on the 9th April 2016. took it back to then after wearing it once for a fun walk which was hell due to the agony the shoes put my feet in. They told me the shoes have to be send back for inspection and that they would contact me after two weeks. Two weeks and two days later I phone them and get told they will find out what is going on and will get to me the same day. The next day I call back, because I heard nothing back from them. All they have to say then is that, there is nothing wrong with the shoes and they won't refund or exchange. Phone MR Price head office then and after phoning back and forth, got the same answer. What am I supposed to do? When I bought the shoes I asked the sales person for shoes to walk/run in. I was looking at other shoes, then he told me NO buy these they are the best shoes for what I need. Now after finding out that is not true, I'm stuck with "sorry we cant help you"... What kind of service is that? They are supposed to be the people who know about sports equipment, but then if they are wrong all you get is sorry...?