I HATE to suggest this, because I don't agree with animals being put on Freecycle but have you tried on there? Femi (the rat I rehomed last year) was from my local Freecycle. She was supposedly unable to bond with females and now lives with a group of three!
I also have to agree with other comments on here. I've been to petshops in the past when I couldn't find companions for obviously unhappy animals. It's not ideal for us, but necessary for them. Although there was never a shortage of ferrets - when I lost Odin, the last of my "business" I called the rescue lady I got two of my three from. She symphathised, and then told me about a castrated male needing a home. Not in an insensitive way, I was quite flattered as she isn't the type to rehome too readily. I didn't really feel i could give him the attention and had to say no, sadly.
Anyway, back on track! I'm off to check random pages and see if I can locate a girlfriend for Spot!