SHiFT Services for Borderlands 2 on the PlayStation Vita will be undergoing maintenance starting today, March 25, 2015.
Users will experience the inability to redeem SHiFT codes, but should not experience any interruption to the ability to utilize Borderlands 2’s Cross Save feature.
For updates, please keep an eye on https://gearboxsoftware.zendesk.com/entries/65150510-SHiFT-Maintenance-for-PlayStation-Vita and @SHiFTStatus on Twitter.
Ah, thanks for posting this. I’ve spent 45 minutes trying to troubleshoot why I couldn’t login.
BUTTTTTTTTTTTTTT…the big question!
If I cannot login today, how will I redeem the Shift codes that are good for today ?! 
Send a ticket to the Gearbox Helpdesk here: https://gearboxsoftware.zendesk.com/anonymous_requests/new
I also did it, just tell them your issue and than which golden keys you wanted to add, they will add them to your account and when the PS Vita shift server will be online again will you be able to use them.
I also did it yesterday 
I like the service that Gearbox is delivering 
thanks i got the keys for the codes i was missing
In germany the problem with the shift server still exists.
Have you any solutions to solve it?
Thank you and best regards.
Still waiting for using shift code on Ps Vita.Please bring it backkk.
SHiFT functionality has been restored for Borderlands 2 on PlayStation Vita! If you have issues with SHiFT or Borderlands 2, please visit http://support.gearboxsoftware.com.
can you help me about DLC3 and DLC4 ?