M&S polo shirt

[Whyriskit]

DS1 started P1 (scotland) 3 weeks ago. As well as his logoed polo shirts, I bought a 2 pack of M&S ones for when i couldn't be arsed ironing emergencies.
He wore one once, developed a big hole at a seam. Took it back to be told that as it was a twin pack, I need to return both. Not a big deal - but would you have assumed you'd have to take both back?

I wouldn't have assumed it but it does make sense.

If they sell them in pairs, they would have to give you another two pack in exchange.

Common sense and logic would tell me that both would have to be returned. yes.