This is why it is wise to read cancellation policies for TAs as well as for cruise lines.A shame you are being stung for something not your fault. BTW, if you had paid the deposit by credit card, try a reclaim for service not delivered.
When cruising overseas, we have bought the duty free alcohol for cruise friends that were doing B2Bs and have also been the recipient of such a favour.
We have also loaded extra credit onto the card if our expenses are likely to exceed the limit and / or we would still be away for the first months payment.