Check the local laws relevant to protection for consumers and relevant to sales claims and advertising and contracts. Check their T&C’s for circumstances under which they would offer a refund or partial refund.
No firm is going to be happy with a consumer who pays a deposit and then does not take up the service agreed to. That’s what deposits are supposed to prevent.
But you might find that if you argue enough they will make a refund even if they have done nothing wrong, simply to preserve goodwill and so that they can get on with their real business with real customers.