Travel Credits Disappeared

This is a post from a travel perspective for a change. Has anyone had your travel credits disappear? I just sent this to Airbnb and I’d like to know if anyone else has had this experience:
“This is the second time this has happened to me. There is a discrepancy between the app and using the computer with credits/coupons. At the beginning of 2018 I had 3 travel credits, one $35 and the other two $25 each. The first one was expiring February 2018 so I used that one recently. The other two expired much later in 2018, I don’t remember dates exactly but in the second half of the year. They have NOT been used and they have disappeared.
The first time this happened I did have a screenshot of the credit sitting on my app. This time I foolishly did not so it seems Airbnb won’t believe me and I have lost them.
How is it possible that a) there can be a discrepancy between the two systems and b) that they just disappear??
I’m not very happy with this especially as it’s happened twice now.”