So i cant change my ip address when someone ban my ip?
What the hell did you do, I wonder 
Your internal IP address (192.XXX.X.XXX) is unique, and that can
identify your computer from your router. Then there's another IP
which your ISP can use to differentiate between you and the other
customers. Then there's the external IP, which the websites and
servers you visit will see. Say you are a SingNet subscriber,
Internal IP will be 192.168.X.XXX which will be unique to people.
External IP will usually be 220.XXX.X.XXX. Many ISPs use dynamic
IP, and they will switch it around. So many customers will use the
few different IPs. If they ban one IP, means many will be affected,
if it so happens that they try to connect using the IP, or they
might ban the whole range, so everyone can't access it.
You better hope they never ban the 220.XXX.X.XXX IP, and that
they instead banned the 192.XXX.X.XXX IP. You can try to get the
DNS server to try and change IP, by asking it to assign you a new
one.