Zain is offering the renumbering service for your contacts with no charges. All what you have to do is to follow the instruction.
1. Check if your mobile is supported or not, for the complete list of supported devices click here
2. Send SMS with the letter B to the number 99509.
You will receive two messages, the first one for login purpose to Zain portal, click on the link provided on this message. notice that when you enter the link you'll be using the Internet service which is also free for now!
when you enter the website a list with brand names will show up. After choosing your mobile brand, another list for your phone models will show up, select the model and install the software.
The second message provides the link for the same instruction which is already mentioned here!
4. Open the client and click on Profiles. "check your mobile for the client application that you've already installed".
5. Choose Contacts
6. Go back, click on Keep It (some mobiles starts Keeping automatically)
7. Click on Get It
8. Your contacts are renumbered now you may face some delay due to sever load, you can do a direct renumbering through Zain Mobile Backup Portal
Once you installed the program your info will be stored in a portal service provided by Zain. So I am not sure about how confidentially they take your info. I spoke to Zain and they said your information will be kept confidential though.
What else you can do with " Zain Mobile Client" application?
1- you can backup/synchronize your mobile entire date.
2- manage/view your data through Zain secure server.
3- transfer your backup date to new mobile.
Since I am using Nokia, I renumbered my contacts list using Nokia PC Suite software. it is also useful for backup purposes. in this case what matter happened to the data on your mobile "Damaged/erased/lost/stolen" you'll be having a backup version on your PC to reinstall it later on.