2000 at the immigration, but if for some reason the police check your passport and catch you with it, then it will cost 5,000. Funnywise on my Chiang Mai TM47 form it is written that it cost in any case 5000
At the bottom of the TM.47 form it's written: "The fine of Overdue Notification is not exceeding 5000 Baht". Thats why I'm using the calendar function of my phone to remind me of the 90 days notification 😉
You should first try to find out what was the reason for rejection. I would travel to a new consulate in another country. Just in case they rejected you because they didn't like you for whatever reason
Of course, it's not normal. Normally, you should have received a DTV, but maybe it was a mistake. You could go back to the counter where you paid the 10,000 baht, which is open in the morning, and ask if it was perhaps a mistake because you applied for a DTV
The reason your visa hasn't been approved yet could be that, in view of the growing tensions, the consular staff are apparently fully occupied with preparing evacuation plans for Thai citizens and the consulate itself. I can well imagine that ordinary visa applications are simply not a priority.