Phone numbers separated from contacts iPhone 4

Hello,

Recently, I have found that my contacts no longer have phone numbers associated with them. In my text messages, I am no longer viewing names of contacts, but their would-be phone numbers. Unfortunately, this means that the only phone numbers I have of my contacts are the phone numbers of the contacts that have texted me somewhat recently. Befuddled, I decided to restore my iPhone via a manual backup from a month ago on my computer. Upon finishing the restoration, my contacts were restored, and I thought that I had solved my problem. Five minutes later, however, there are again no phone numbers associated with my contacts :/

Randomly, there are contacts that do not have this issue. I do not understand why this is, or know if it is of any significance.

Is there some way I can get the numbers back? This is very frustrating.

Thanks for your time in advance