Extremely shocked

I bought about 5 or 6 items from Earthchild and one of the items was big, I wanted to exchange it but I misplaced the slip but they refused to exchange it even though it hasn't been worn and the price tag is still there. I didn't even want a refund I only wanted to exchange it for the right size and I was told that since I don't have a slip I must purchase the same product again and the one that I have I can go sell it to someone else since they cant help me. Seriously I just don't understand. I mean since they take down our numbers to sign us up as loyalty members for discounts or whatever it is they can surely check if you are the one that bought that item and assist. I'm just really shocked and disgusted on how I was treated, being a regular buyer at this store and be treated like this hell no I disagree. Then I logged a complaint in December when this happen I was told someone will call me back which never happened, I called again now in January I was told someone will call me back again no one called, I call again today and I'm told that no one has even touched the complaint, no one is working on it wow wouldn't you say that is some GOOD CUSTOMER SERVICE. Clearly earthchild does not take customer service serious and don't even care about their customers.