No you can't call for your own reservation, as it isn't owned by you. That's the thing you give up when you use a TA.
I assume you are overseas, and calling is difficult? If that's the case I can see why you wanted a TA, but otherwise, I can't see having a middleman as being faster.
DU is supposed to be good, so I don't know why there's the delay for you. Hope it gets worked out quickly.