Hello @Marzieh4
Write back to the guest and say you are sorry that they didn't check that your listing was in the location they wanted. Confirm that they have done the right thing in approaching airbnb to process their cancellation..
Let them know that you won't be able to agree to them having an additional refund to that, that they would be entitled to under the cancellation policy they booked under.
However, say as a gesture of goodwill IF you are able to re-book any of the days that they cancelled, you will consider a refund from your side of any dates that are re-booked.
Then decline their request for an additional refund.
In this way you won't be out of pocket and you are being flexible in offering the guest a refund for any dates you get rebooked, which is showing you to be flexible. (Of course the guest might not see it this way, but please stand firm).
Leave your guest an honest review.