Cotton On Sent Me the Wrong Size Twice and Customer Service Was Unhelpful

The last time I used Cotton On's online store was a pain, and I don't think I'll be shopping there again. They sent me the wrong size of jeans when I asked for a certain size. I thought it was just a mistake, so I sent them back and ordered the same pair again. But they sent the wrong size again! When I called customer service, they weren't very helpful. They barely said sorry and didn't offer a real answer. Dealing with the same mistake twice is very disappointing, and the lack of proper help made things even worse. It seems like they don't care about their customers.