Are ankle guards considered underwear ?

I purchased a ankle guard at mrp sport in Kenilworth Centre. The following week I took it back as it didn’t fit. I was told by one of the cashiers that due to covid safety measures they don’t allow exchanges of an ankle guard.

Now I understand why certain items of clothing etc cannot be exchanged for hygiene but according to mrp terms, underwear, jewelry and cosmetics may not be exchanged.

Ankle guards are not considered underwear so I don’t understand why it couldn’t be exchanged. If using covid safety measures as a reason for no exchange then technically nothing should be allowed to be exchanged.

Please clarify me on this.