Must .... not .... troll ...
The simpliest solution would be to buy another one, considering there's -75% on warband. If I understood correctly, you were playing fine until today, which means that either servers got problems, or your key got a problem. Try to check if it's about servers refusing serial keys (happened in the past), and if it's not, give a try to the technical assistance. If you already did that, the easy solution still stands.