[US] Suspicious (to me) Return.

I work customer service at a department store. I had a lady return a fish tank kit, light, and several fish. Only brought 1 dead one though. I processed that return. Each item was on a different receipt and the system told me one of those receipts had processed a return for more fish back at the end of last month. She told me a sob story about how they had died and she didn’t want to talk about it.

This person returned 2 hours later and bought more fish.

Is there something going on I should report? Or has it just been a long shift?