Welcome to the forum!!
Your hamster is a hybrid of both Winter White and Campbell
Do you live in the USA or UK? If you live in the USA I don't think there are any Pedigree Winter White breeders and for Pedigree Campbells there is one 1 breeder.
If you're in the UK - You can usually find Winter Whites for sale at Hamster shows. Aside from that there is Oblivion Hamstery, Hamster Mischief, Winterwood Hamstery, Tuftyfluff, Tristar, Wellington and Lilliput - Those are the names on my Winter Whites Pedigree, so, some of them may not be breeding them anymore/may not be currently breeding them.
Hope this helps!