Receiving gifts you don't like

Is

My SO is really sweet and knows I have a hard time spending money on myself so he's being all sweet and doing it for me. The thing is I don't like the things he gets me. He insists on buying clothes for me, but they don't fit me well, aren't in colours I like and not in my style. I've tried to gently tell him but he doesn't keep the receipts so I can change them and he doesn't seem to care. I'm really grateful, it's sweet. But we're a bit short on money so I feel even more stupid for having all these clothes I can't even use. What do I do? ☹