The ISP is owned by the group who own the apartments around here
Do you actually have your own independent internet connection? A DSL or cable line or whatever it is, connected to a modem in
your household?
Or do you just have an ethernet cable line given to you, and all your connections split of off that?
You need to have the former to be able to port forward. If it's the latter, all the NAT operations are handled by the first router, the one connected adjacent to the modem, which since you don't have access to, you can't port forward
EDIT: I just remembered it was you who posted
this threadIt's the latter