Male White Finch Is Quiet and Sleepy?

Thanks for your comments and solution that worked for you! I just bought a male and female bonded pair last Saturday and the male was puffed up when I bought him but never having had birds before I didnt know it could indicate illness. I was told at the store that possibly someone tapped on the glass and stressed him out.

Well I brought them home and he seemed fine that night and I put a nest in the cage. They took to it by the next day but the male puffed back out and has been only coming out to eat and keeps retreating to the nest. I called the store that I bought them from and told them what is happening and was told to just watch them and if he stops eating and drinking to bring him back and their vet would look at him. He has been either eating alot or just flinging the seed all over and cant even do the usual flying exercises they do and he has even fallen off a purch while trying to hop from purch to purch. He seems fat but it's hard to tell with puffy feathers.
What are neem leaves and where do I get those? What are the used for?
I too tried to give them a bath to splash in all to no avail. So I misted them (when he looked normal that 2nd day) and then worried it might have been too soon as they might not have even settled in enough yet. I put a thermometer on the cage and it has been consistently 71 degrees. I worried I made him catch cold or something by misting them. No more of that until I know what is going on with him.
He seems to have rallied just a little this morning. Still puffed out and at the seed dish a lot. But I think with the females urging he has come out of the nest a bit more and hopped from purch to purch but still puffy and no flying. Also they havent touched any fresh vegetables or fruit I've offered. I think they've never been given it before and dont know what to do with it. Which makes me a bit mad at the store for never giving them anything their whole lives. They also said they think they are about 8 months old. But maybe the male is old and that's why hes like this? I just dont know. Any help would be appreciated. I have one more week for them to be under their 14 day guarantee. Also, if he does die, would the female bond to another male? I'm worried if he does die the female may die too if the store cant get me another male or she doesn't bond with another male. Thanks for any help I can get!