There is no website where you can register. You will have to call them up at 1-800-11-4000. You can get local addresses of their offices at:
http://www.ncdrc.nic.in/
In the first instance, they will put you in touch with higher people within the concerned company who have more power to negotiate and solve problems.
In the second instance, you will be asked to formally file a complaint at your local NCDRC office. You will be required to produce evidence for every statement you make. If you say you handed over your laptop on 09-11-08, you must have a receipt to that effect, etc.