This is a great post and perfect example.
These things happen at Chrono 24, but in general, my experience with the website is very good.
What I have experienced was the fact that I bought and paid for a watch, but the seller returned the money
and sold it to someone else, who offered more money.
(after paying the watch is indicated as reserved)
These kinds of things are possible and Chrono24 does not do anything to help.