How old is it? How have you've stored it? If it's reasonably new and only been used indoors you should complain. If you haven't cared for it it's most likely your own fault. Rottening is an inevitable process, tanning just temporarily prevents it, specially if you've been sleeping out with it, without caring for it. Like leather it needs a rub of leather balm or similar stuff on the fleshside every now and then.
EDIT: just reread and saw that it was only a couple of months old, you should talk to the tanners!
EDIT2: Tanned furry hides always looses some hairs. It's natural and is dependent of the time of year the animal was slaughtered and how the hide was treated before tanning. But if it's coming off in big lumps there is something wrong.