BB&B may cost more than Target, but IME, they have some of the most liberal return policies of any store.
Not long ago, we bought a surprisingly expensive Aerobed there. The morning after its first use, I found one of our guests sleeping on the couch and the other woke up on the floor, surrounded by a deflated bed. In the time between buying it with a 20% coupon and returning it, we’d lost the receipt. (Any piece of paper smaller than a poster is endangered in my house.)
We bought the thing mainly for our guests to use, and when they found this out, they protested and said they’d be fine with a sleeping bag on the floor. So, we rolled the thing up and went back to the store, not knowing if we’d be able to return it at all, or if we’d have to either take another in exchange, or even worse, ship the leaky and very heavy thing back to the manufacturer.
They gave us a store credit for the full non-coupon price. No quibbles, no taking of IDs. We very happily turned that into a couple small kitchen appliances.
As for the question of if it’s ethical to use multiple coupons, expired coupons or to receive full value on returning something that was bought with a coupon, I see no problems at all. The company is not showing any signs of financial troubles, and if their unwritten policies are to accept any and all coupons, and to issue refunds as if no coupon had been used, that’s up to them. You’re not doing anything sneaky.
In the end, it’s a win for them. They’re not losing 20% when they give a full-value credit. They’re just getting a 30% markup instead of 50%. The returned merchandise goes back to the maker for credit, so it’s not like the store is out much other than the overhead cost of handling the thing. (eg: the hourly wages of whoever takes in the return) They also get return customers. Returning customers, or what the industry calls “same-store” sales are a HUGE factor in gauging how well a company is doing. When those returning customers are happy, it’s even better.