Really you don't get any Death Valley badges. I've been at the same number and been farming for a few hours. You only get a badge if you complete the level. Since you get a Mission Failure you don't get a badge but you do get the prize.
Now Lockdown is another story. You will have a greater chance of getting banned farming euros from LD. Unless you can make it to were you don't get EXP or badges but just get supply points that you shouldn't get banned.
The people who know how to add 1million euros every hour, know how to do not get EXP or badges but massive supply points.