I was on the Net10 30 day monthly plan of 750 minutes. I went to my Dollar General store and purchased this card, $25.00 "30 day monthly plan 750 minutes" and my phone says the airtime pin is invalid. I spent $25.00 on this card. I tried 3 times for customer service and technichal support to help me, and they seemd confused, and ended up saying I needed to be on another phone with them. I 'reactivated' my phone on the computer, but it says my phone is already active. Granted, I tried to apply the new minutes---after--- the 30 days. What do I do now?