I'm not sure what platform you are using since you didn't specify. I totally understand your frustration...having been a former customer support rep (but not at Google!).
If you are using DFP Premium (paid product)...then check with whoever has the contract...they should have a contact for you to reach out to. Support is part of the paid package.
If you are using DFP Small Business...remember that it's free, so you get limited (very) support. This is a peer supported forum primarily...though Google folks pop in sometimes. Free is great, but sometimes comes up a bit shy in the support department...remember that you are getting a great product for nothing (well...maybe frustration is the price?).