Even if the date was entered correctly, they're not under any obligation to remind you of the stepup option. It's a selling point, just like it is with EVGA, but it's up to you to pursue the option within the time frame. Had you done so, and attempted to stepup, you would have encountered the incorrect date and been able to remedy it, using the same steps you just underwent, except that it would have been fixed within the eligible time period.
__________________ i7 2600K | ASUS Maximus IV GENE-Z | GTX Titan | Corsair DDR3-2133 |