Issues with ISP side proxy servers and changing ip address

[Question2]

I live in a country where all IP addresses are dynamic and all ISPs use ISP side proxy servers...

This has of course caused problems, because if someone using the same proxy server as yours acts stupid, you would probably end up banned too.

This used to be easily solved by doing an IP reset...using ipconfig /release, /flushdns, and then resetting the modem. At most this took only a few tries.

I recently switched ISPs, and have now tried to change my IP again, but it does not seem to be working despite 5+ tries. The ban message keeps coming up, and its the same ip everytime(probably the proxy server, my ipv4 address in ipconfig is different from that one, although the ipv4 address keeps showing up as the same despite multiple attempts to reset my ip).

Is there anything i can do about this? Am i doing the IP reset correctly(tried the method on the site, does not appear to have changed anything), because i dont think the IP itself is changing. The site admin is famous for not responding to attempts to contact him, and appeals to bans are usually not even considered regardless of how valid it is.