Sale item can't be returned.

I purchased a bedding set on the 25th of August 2021. And wanted to return it and I am being told that I can't however the unit is still in its original packaging and I have a valid till slip that stipulates I (customer) have a 30 day exchange period.

I already found something else. Similar so I won't be needing that Besser anymore.

What is infuriating is that this new policy was not made clear upon my purchase but today (02/09/2021) when I want to make the refund.