A customer calls the store
Customer: I'd like to return a book I bought.
Me: Okay, do you have the receipt?
Me: It shouldn't be a problem, as long as it hasn't been more than a week and it's still in sale-able condition.
Customer: Great. I'll see you later.
The customer comes in later that day.
Customer: Hi, I called earlier and you said I could return this.
Me: Sure, I just need your receipt.
He hands me his receipt.
It's for a different store.
Not a different location of our store or something, a COMPLETELY different store.
Me: Sir, this receipt isn't for this store.
Customer: Yeah, I know. I didn't buy it here.
Me: Ummmm, I can't return it here if you didn't buy it here.
Customer: Well you didn't say that when I called.
Me: If you'd mentioned you hadn't purchased the book here I would have told you we couldn't return it. Generally we assume that if you call here asking to return something you bought it here. That's the reason you need a receipt, to show you bought it here.
1 hour ago