Easy way to check the fans are working, is to go for a 15 minute
drive, leave aircon off. Find out at what temp the fan/s should
kick in, then leave it ticking over on the driveway.
Watch the temp, and wait and see if the fan kicks in.
this way you will prove or disprove if its fan related.
Note most fans have two speeds, the first one may come on at 93/95 degrees [ the book should telll you, or try a vw forum]
then the second fan or second speed may come on 3/5 degrees
later.
sometimes it can be that the first speed/fan or the second speed/fan is not working.
Either way you should be able to eliminate or prove that the fans are not/are ok.