Booking.com Commission being charged on local tourist tax


I just noticed recently that Bookings.com is charging Commission on local tourist tax (which is a daily charge per person). I tried removing the local tourist tax from my invoices but it does not seem to give me the option. Has anyone else had this problem? It seems unfair that Booking.com is making a profit from money that does not go to the property owner. 

I have tried emailing bookings.com from the extranet but so far they have not answered my question.

Best wishes