Tier 4 - how to exchange a shop bought item

[ZigZagInToChristmas]

When my area was in tier 2 my DH bought me an item from Fat Face for Christmas. Unfortunately it was the wrong size and as of today we are in tier 4 so I can't take it to the shop to exchange. Does anyone know how I can go about exchanging a shop bought item when in Tier 4? The Fat Face website doesn't answer this question.

Can it be returned by post and a new one ordered for collection/to be posted?

Thanks @dementedpixie In the end the answer was to print off a returns label from the website and return the item with the receipt. If only they had this clearly stated on their website!