Alteration taxes

[Derek-and-Jill1]

We had a guest book for 13 nights. As soon as they arrived it was obviously they were trying to get out of the reservation by finding frivolous things wrong with the house. (Freezer door closed to slow, AC in 1 room took too long to ramp up, etc. ) The guest demanded full money back within 1 hr of arriving. Airbnb determined we were not at fault, the house was in excellent condition and we were within our rights to keep the entire amount without providing a refund. However they asked me to consider refunding in accord with Airbnb fair practices. We agreed it would be fine, the guest would pay for 2 nights and the cleaning fee. This would cover the house downtime and the cleaning. 
We received our payout later, with the next guests payout. Airbnb deducted both income and vat taxes for the entire 13 night stay, instead of just on the 2 nights/cleaning. They refuse to reimburse the taxes, saying it has already been completed. Suffice to say, we actually lost a fair bit of money on the transaction. I’m sure they adjusted the taxes the guest paid to match the 2 nights/cleaning. Im not sure what to do now, any suggestions?

[Emiel1]

@Derek-and-Jill1 

Not clear how (canceled shortened ?) and by whom (Host, Guest,Airbnb ?) the reservation was ended.

Useally best option to do is:

The host must shorten the reservation to 2 nights ("change" option on the reservation).

Then renting price is calculated accordingly. If price is not correct, host can amend the price in the change-form. VAT and Taxes will be calculated also automaticelly regarding a two nights stay.

Never let Airbnb CS  perform such changes, they often make mistakes.