@rajan: Thanks for the link, but that app cannot be installed on the motorola photon. Also I tried other dialers (https://market.android.com/details?id=com.iba.ussdchecker&feature=related_apps) but same thing as I have mentioned in the above post.
I remembered that while using the blackberry, I would dial 121 (customercare) and then as a conference call dial the USSD code. That would make it work on the blackberry.
Tried it on the motorola photon but that also does not work.