Hmm we do not know what we can do and if it is possible to cancel ispconfig and install other CP
Not sure why you want to do this. If ispconfig works fine on thousands of servers it will work on yours too. So you should just check your system why the IP addresses wont work.
1) Check with the command "ifconfig" that your network card has the correct IP's configured.
2) Add the Ip addresses in ISPConfig.
3) Add a website in ISPConfig were you select the IP address.
4) Make sure that the domain of this website really points to the selected IP address with a dns A-Record. Be aware that changes in dns take up to 48 hours and that your site will work only with a correct dns record of course.