Ours was rejected once for no reason, we resubmitted and it went fine. Then another time it turned out one of us went on a short trip and stayed in a hotel, so TM-30 had to be reregistered again... Just try again, and if not - physically apply to immigration office.
We went yesterday to the Embassy in our country regarding STV visa, and they said that even if we obtain one, we need to leave Thailand by Sept30th 🙄 So it's basically useless