Are you calling from the UK? If you are the number you would dial is 004970022237784
I hear you, but for whatever reason that's not solved your problem.
Obviously, I have no idea what's actually happened as I don't work for them but I'm starting to think that the guys from Access might be under the impression that they have already sent the Mac application mentioned in the emails you had earlier & closed the ticket. Again, I have no idea how their system works but if that's the case then it's possible that when you are replying with your original ticket no. this has been getting routed straight to a dead letterbox.
I'm only thinking something like this because allowing a problem like you have to go on for such a long time unresolved doesn't sound like the kind of thing they would normally do & if they thought that your machine was stolen or belonged to someone else then seeing as you have already sent them your address you would think the police would have visited you by now.
EDIT: Oh yea, don't forget the times the phone support is available is in German local time so you will have to make any adjustments for where you are calling from.