Thanks for your enquiry.
I know it's crazy, but clients are under a duty to cancel their Home insurance arranged through any Mortgage Lender, even though the Lender is aware of any Sale.
Legally, I'm afraid you have no chance of recouping your loss on any paid premiums.
The best you can hope for is if your Lender makes a goodwill gesture and offers some sort of reimbursement, but please don't count on it.
I am sorry this is not the answer you were looking for, but if I have answered your question, I would be grateful if you could leave positive feedback.