Get the money back off the bike shop, why support their cash flow, I bet they wont be giving you a nice discount when you eventually do buy some thing. As above what happens if they go bust tomorrow?
Being unemployed is not nice and I think its good to keep doing things you enjoy, as when I have been out of work, even for only a matter of weeks its an awful feeling and can lead to depression all too easily.
However, don’t take this the wrong way, but you really need to get priorities right, if your strapped for cash why buy a new amp when second hand will do, and get some self control when it comes to finances, it will only work to your favour in the longterm.
Oh yeah and the Q, well ask for the money back, its yours, you dont have to justify it. If its a good LBS they will be happy to do it and hopefully will just say come back when your ready. If its a bad LBS they will get in a huff and then loose your business for ever…(this appears to be the shorted sighted approach of many LBS owners)