Purchase of wrong size of I watch

Hi,

I am not sure if you can help? but I bough my husband and I Watch from a large department store in Ireland. I didn't realise there were different sizes as there was not an option on the site. I bought the 40 and he wanted the 44 mm. I have been back and forth with the shop and they actually took it back as we hadn't taken it out of the box, but the plastic wrap got stuck on the packaging and came off when we took it out of the box. They asked us to send it back so they could take a look, and I heard nothing, and then today the same watch came back with no communication. Can I not return it, you can see it had not been taken out of the box. I am beside myself its cost a lot of money and the face is too small for him.

Your advice would be welcome.

Kind regards,

Polly