hi
Did you get the shop's T/C's? were you told about your deposit, whether it was returnable or not in-case of cancellation? If yes then have a look if they have a certain rule about deposits in their T and C's. If not then ask them that they did not inform you the deposit was non-returnable in-case you decided to cancel, so you are entitled to your full deposit back.
Most shops have their own T/C's and they keep to them, but some have a heart and return a deposit back through goodwill. So your best bet is to ask them.
Thanks