To be honest, had I seen this happen, I would have bought the rattie (an friend), taken it out to the car, set him up, went back in......and promptly be banned for the string of explicits coming from my mouth. lol.
The skin won't grow back, what usually happens is you clip the exposed bone off with nail clippers or the sort, and apply neosporin, and keep it in a safe, dry area where nothing can get stuck to the tail (like cloth bedding), thats about all a vet will do as well......
I'd call the manager, and the head quarters to the store, then post an open article in the paper.....or sue for emotional stress and trauma, lol (well, you can sue over just about everything now!)
3 Cats--Tegan, Tempest, & Faolan
2 Hammies--Lola *f*, an Dizzy*m*
Enigma-mismarked split cap b/w dumbo boy
Ghost- himilayan, standard ear, rex boy
Tierney--Verigated, dumbo, rex boy
Honey-b/w standard ear hooded
Lotus--b/w stanard ear verigated.