Videocon Industries — change/ transfer my rtn number

Respected sir,
As I mentioned below I have a problem with customer care .my old RTN is lost two days ago.I want to change my RTN . But as I go to your website it demands me for password . Before one month my sister edited the password and she had forgotton so can you Please change my RTN or contact me for the change in RTN. As I tried to contact your customer care services they are in available.so, sir please solve my problem.bevause I want to choose my channels and recharge my account immediately.
So please sir solve my problem
Change my RTN from
Old RTN ([protected])
To
New RTN ([protected])