My address for my house is on Booking.com as 28 but we are 28a and I cant seem to change it

Hi, I have listed my house with booking.com but I don't seem o be able to change the address from 28 to 28a. I have an option to edit lots of things but not the address. When I asked for help I was informed that a letter would be sent to me within 60 days! and I could change it then! There are 2 issues with this- The letter will go to the wrong address and also 60 days is a long time! Any chance you can advise please