Hello - I've had a look.
Regarding the puppy conditions in Belarus, this is out of our area so not much we could do with regards to this aspect.
Once the dogs are in the UK it's possible we could look into it though. I'd suggest you send a report via:
www.rspca.org.uk/myrspca detailing all the health problems diagnosed by the vet (do you have vet records/invoices? Handy to have as evidence too) along with full details of the situation. If it sounds as if the Animal Welfare Act is being broken we will investigate and we will act as much as we can. It sounds really frustrating - I hope we're able to help in some way but please do bear in mind we have no powers beyond what your average member of the public does so can only act if a law is being broken - & even then it has to be on the say so of police and vets.
I'd suggest you also keep persevering with trading standards.
I hope this helps and you manage to get it sorted soon :) And hope your pup's OK!