No exchange on factory fault boots

I bought a pair of boots at Rage Brits last year June, only to find when I got home that the pair was two right foot boots. I then took back the pair weeks later to find that they were out of stock a the store manager advised that I should wait for the person who bought the missing left shoe to bring it back so that we could exchange. They took my contact details and advised me to wait for their call. I waited as they said till two weeks back when i went back to the store and asked for an exchange or a full refund. Again they asked to take my numbers because their phone in the store was not working, again they didn't call me back till I sent my sister to ask them if they did my exchange only to find out that they cant assist me. What am I supposed to do with two right foot boots? Rage refuses to take responsibility.