it's a bit of a faux pas on here. pet shops arent the most popular of places on this forum, which is probably why you're getting little to no replies. and plus, most of the users here are american and canadian.
I'm from Glasgow and to be honest Scotland doesn't have a lot of good rat breeders. My local petshop get loads in but I have no idea where from. Plus usually good breeders don't have a lot of ratlets at a time so it's hard to get a large amount from a good breeder. Anyway good luck. Why don't you check other pet shops suppliers? and see if they are any good.