NUC not working

[GV19]

I received 2 separate unlock codes and neither worked. I repeatedly got the 'unsuccessful ' message. 

I had entered the correct imei and NUC numbers. The phone I'm trying to unlock is a Sony Experia... the phone is now showing 0 more attempts. 

What's my next step and why after the NUC not working?

[BandOfBrothers]

If a phone becomes hardlocked due to too many attempts to unlock it i.e 0 attempts then a Nuc won't work until Vodafone have sent it off to have it's counter reset @GV19 

A Vodafone Highstreet Store can send it away.

[GV19]

Thanks @bandofbrothers