Refund for laybye

I bought 3 dresses, 2 for my daughters and one for my sister. The dress doesn't fit her,i lost the slip now they are telling me I cannot refund me. I made 3 transactions on that day using my card, what's so difficult about tracing those transactions. I'm so disappointed cz I had told myself that I will never set foot at truworths, after so many years this is what I get, I guess some things will never change!