I keep getting the follow error messages when I try to sign into iTunes store or redeem a song code: We could not complete your iTunes store request. The network connection could not be established. There was an error in the iTunes store, please try again

Question

I keep getting the following error messages on my Mac when I try to redeem a song code: "We could not complete your iTunes store request. The network connection could not be established. There was an error in the iTunes store, please try again later."  and then, "We could not complete your iTunes Store request. An unknown error occurred (-50)."

Answer 1

Hello, constance132. 
Thank you for visiting Apple Support Communities. 
Here are some troubleshooting steps that I could recommend when receiving error -50. 
"Error -50," "-5000," "8003," "8008," or "-42023"
These alerts occur due to timeouts or conflicts trying to write a file during download.
If you encounter this issue while accessing iTunes Store:
See iTunes 9: "One Moment Please" or "Error (-50)" message when accessing iTunes Store
If you encounter this issue while while downloading something from the iTunes Store:
Delete your iTunes Downloads folder, located in:
Mac OS X:
  ~/Music/iTunes/iTunes Media/Downloads   Note: "iTunes Media" may appear as "iTunes Music. Also, the tilde (~) refers to your Home directory.
Windows Vista:
  \Users\username\Music\iTunes\iTunes Media\Downloads\
Windows 7:
  \Users\username\My Music\iTunes\iTunes Media\Downloads\
Windows XP:
  \Documents and Settings\username\My Documents\My Music\iTunes\iTunes Media\Downloads\
After locating your iTunes Downloads folder:
Quit iTunes.
Delete the Downloads folder on your computer.
Open iTunes.
Choose Store > Check for Available Downloads.
Enter your account name and password.
If you encounter this issue while while downloading Digital Copies using Windows:
Use MSCONFIG (directions for Windows XP and Windows Vista/Windows 7) to disable conflicting software.
If using MSCONFIG steps resolves the issue, you may want to use the System Configuration Utility to turn on the third-party System Services and Startup Items one at a time (restarting your computer after turning on the item or items) to identify which System Service or Startup Item is causing the conflict.
You can turn all of them back on by selecting the Normal Startup option under the General tab of the System Configuration Utility window, but please note that this may cause the issue to reoccur.
If you are able to isolate the issue to a particular third-party software, you may wish to contact them to let them know of the conflict.
iTunes: Advanced iTunes Store troubleshooting
http://support.apple.com/kb/TS3297
Cheers,
Jason H.