What were you expecting? Were you expected to be treated like a VIP. Did you expect the flight attendant to come around every 30 seconds and fill up your drink? Did you even try to be nice to the flight attendants?

I've flown in Economy Class and have been treated better than you were treated. A Bitte and Danke go a long way. I know people have their off days but I wonder what made them "single" you out.

Perhaps there is something the OP is leaving out. I've flown in the Premium Cabin and not one flight attendant singled me out.

Now if the Gate Agent sat you upstairs there should have been a reflection of this on the manifest. If the Gate Agent approved it then why should the flight attendants have a problem.