It seems there are two possible issues here:
The first is what is simply known as the Space Center Great Work bug. Basically, the space center is not connected to the world's regional freeway and cannot receive new works and may not be receiving donated materials too. You'll likely need a mod to fix it (two are provided in the link above).
The second is that Simcity 2013 servers aren't syncing with the EA/Origin client properly. Supplies you send are basically lost. Check your internet for connectivity issues, transition to single player mode, or check on the game in an hour or two and see if the error has fixed itself.
There are other potential reasons this can happen but from what I've read these are the two most common.