I don't know a great deal about what rescues are in the area but if you can get to Dawlish on 5th March, there's a hamster show hosted by the Southern Hamster Club where they may have hamsters available for sale or you could arrange to pick up a hamster there from a Club Breeder if they are attending.
The details you need, if you're interested can be found:
http://hamsters-uk.org/showdocuments...awlish2022.pdf