I want my refund

In February I bought a smart watch which was advertised that it had 8 gig of space. I received a 4 gig one. I sent it back an asked for a new one, after following up a number of times I was told that they made a mistake, it is actually 4 gigs not 8. Ok fine, I said they can give me the watch. After following numerous times AGAIN I was told that the watch is not in stock, they will let me know when it will be in stock. After weeks of waiting and chasing after them they said the watch is in stock and it's on it's way. After waiting a while I asked them to cancel the order and give me a refund rather. Its been 2 weeks waiting, I have been following up with no response. I am at my wits end now. I don't have a watch, my money is gone and it's not fair