You must really like this site. I bet its something silly... "How did you change your IP on the router?" You physically released and renewed to your provider AND it's a physically different IP? (Double check cuz I bet that didnt happen)... after that step "didn't happen" you probably attempted a transparent proxy which still indeed shows your IP address... (which was never really changed).
Oh yeah, it's for a really stupid site lol.
Anyways my ip changed from www.xxx.yyy.zzz to www.xxx.aaa.bbb. I'm guessing they banned www.xxx.*.*?
I tried a proxy(from here) and Tor browser which should both hide my IP. Using "whats my ip" it showed different IPs.
It's really a stupid site, so I can't imagine them going through crazy hoops to ban me.