I have a rain jacket purchased from a different store with the same policy. It's at least 10 years old. The waterproofing is peeling at the seams and the darn thing leaks like a sieve. I called the company and they are happily exchanging it for another. The customer service person said there's normal wear and tear then there's product failure. They guarantee their products and they stand by it. They said since I followed the care instructions and the jacket had light use. Regardless of the fact that it's ten years old+ the lining should not have failed.

As far as your situation. You thought the product would work but it didn't. No reason to feel guilty. It's not like you bought a party dress, left the tags on, wore it for the party and then returned it.