Exchange of apple se watch fir different colour

My partner bought an apple SE watch from Stormfront store in Lincoln which I’m delighted with apart from the colour. So I looked on website and you say that even if it’s been opened it can be exchanged .

I have not worn or set watch or done anything to it!

I called Stormfront a few minutes ago to be told I would not be able to exchange !

could I please have some information regarding where I go from here please?

I wish my partner had now not gone to Stormfront to purchase my gift for my birthday.

many thanks

kim bridges