Hello Silver,
i am so sorry to hear about your bad experience, but to be honest this is sadly not unheard of

actually this is quite common with hamsters from pet shops, especially the larger ones where the hamsters come from 'farms' where they are mass bred to make as much money as possible.
A large percentage of 'pet shop' hamsters are fed on the cheapest food possible which is usually not beneficial at all, they are taken from their mother too early so that they can be sold and so that their mother can be re bred as soon as possible, and they go through so much stress that they usally go to their new homes with numerous problems

It doesnt help that they are not healthy to begin with, so they usually cant cope with the stress and problems they have. It is all very sad, but unfortunately there is not much we can do except
not to buy from pet shops whenever possibleI really cant stress this enough - this is not directed at you Silver, but at anyone who can choose between buying from a pet shop and buying from a reputable hobbyist breeder where the babies will be well bred, fed on the best food, come from parents with known backgrounds etc. etc. If you can get to a breeder, even if it is a bit more effort, or you might have to wait a couple of weeks, travel a bit further etc. then it really is well worth it, as unfortunately silvers story is just too common when buying from pet shops

I really hope that you do complain Silver and get something changed about they are kept and bred, but i know many people who have tried and failed

Tammy x