CID Name Prefix is not working in Ring Group Module

Thanks Tony for your response. Actually you are right but here in my case, the cell phone company, which I am using is showing the caller’s name and phone number both in the following format when I receive the call at my cell phone:

JOHN SMITH
9991115555

Just like a land line or phone attached with the ATA and showing the caller’s ID. Even when I forward my phone number directly from Inbound Routes to my cell phone and put any name in-front of the CID Name Prefix area, it works fine and it shows at my cell as well.
For example, if I put the name “SALE:” as a CID Prefix Name through Inbound Routes modul and then directly forward it to my cell phone it works fine. I receive the calls at my cell phone and the caller’s ID shows in this way:

SALE:JOHN SMITH
9991115555

But this does not work at all through ring group. I receive the calls but CID Name Prefix does not work there at all and it just shows the caller’s ID in this format:

999111555
999111555

It does not show the caller’s ID or even CID Name Prefix (SALE). My problem is, if it is showing through Inbound Routes, the correct CID Name Prefix why it is not showing through Ring Group module? Is there anything which I need to do to fix this problem? Any suggestion…any idea…?