What horrible customer service!
I got a sweater as a gift and they would not let me exchange it despite being in perfect condition with tags on etc. I didn't have the receipt for the sweater but it was a boutique brand which they sell and was over 200 dollars. I asked if they could look up the credit card number or the sku of the sweater and was met with a simple no.
Time to upgrade your system and learn a little customer service.