I'm sorry you weren't able to. Did you have a letter from an employer or did they ask for extra 'fees'?
I help around 100 people per year enter KH with an e-type visa and know for certain that is is possible to get an e-type visa at dom krawlor. It's a remote outpost, and you are entirely subject to the whims of the border officials, so a 'donation' is probably necessary along with the standard e-type visa requirements.