[Kottai]

Need some assistance - ordered two shoes from Adidas, with the idea of doing a partial.
They arrived in separate deliveries, so when I received the more expensive pair, I called them up and said the box was empty. Adidas contacted the warehouse and conducted an investigation.
However seems like I was too eager as the person I got the trainers for informed me that they're way too tight! So having realised that the Ultraboost trainers were worthless to me as they don't fit anyone I'd give the shoes away to and they don't have any resale value, half an hour later I called the customer service again and informed them that I'd found the items and they proceeded to make a note on the system and cancel any investigation.
I have just returned the shoes, and received the other pair from the order today which I was going to actually pay for as they were about £30.
My question is, should I go for a size exchange and try get it refunded again or should I give up and try elsewhere?

First post, sorry if its a bit confusing!