wrong keys given back to me

I had a key cut at Barksole Tygervalley. When i went to try they key, it wouldn't work. <br> <br> When i checked it against the other original i had, it was different. I noticed that the master, as well as the new key were both different to the key i had in my possession. The master given back to me by the shop assistant, was an old weathered key. My lock was brand new, and so were they keys. He had given me the wrong 2 keys back. <br> I went back to the store only to be told by the rude shop assistant, that \ it is impossible