Gee, get over it mate ! Really ! I bet in the next 12 months there will be a sale where you could get the Nevada map with a 50% discount without the need to use your bonus credits.
And who did force you to buy it ?
Go to the ED store, click on the more button, than, at the bottom, there should be a "show serial number" if you are eligable to get the campaign for free. Afterwards, the store should change to "bought" and sooner or later your module manager should tell you the campaign is ready for download ... at least it did for me.
Not sure if necessary but I checked the serial number after I got it via the "more" button with the licence check option in my profile.