Airbnb Coupon rules

[Davor6]

Rules that are made for using a Airbnb coupon are just hypocritical!

They are giving something as a reward for hosts hard work, but only under bunch of demanding and limitation rules.

Personally I only have few free days in year to use 100$ coupon, and when I used only 70 % of it for 1 reservation, the rest is lost permanently? I had to change reservation from 5 to 6 guests, and its charged more. But instead of using the rest of my coupon I have to pay it myself? Why?? They are so penny-pinching, if 100 $ are earned, 100 $ should be given and spent. After 5 years on Airbnb, 11 times in a row being Super Host with published more then 70 apartments and 360 superb reviews so far, I am dissapointed in Airbnb rules and their customer service that couldnt help me with this. 

[Davor6]

I also have a screenshot of the coupon I received last year, and it says that only limitation is that it must be used until 06.07.2019. No words about other bunch of rules, neither link for it.