Yes, black and african is a bad combo to get discriminated against in Thailand, but also in the rest of the world. Which part is confusing to understand...?
How come so many people are not understanding OP post at all? Guys, wake up or just don't comment non sense. OP applied for a wp3 which take 2-3 days to get approved. He need this to apply for a work permit because he is from Nigeria. Geez, this group is becoming worse then the big one which we ran away from to start this one, lol.
I'm not surprised that it's taken so long given that you are from Nigeria. It's not by accident that I mentioned Nigeria above (before knowing which country you are from). Nigerians have a bad rep in Thailand (love scam, call center scam, and other online scams). It's not your fault. You will have the occasional old foreigner shimming in with a personal anecdote and anything under the sun to ignore systemic discrimination. Ignore them, they live in their ivory tower.
It would be easier to come to Thailand on a tourist visa and start the process over. Need a lawyer to make sure you don't get screwed over while here. Thailand have had his fair share of love scam and internet scam from Nigeria and other African countries therefore they often are very paranoid about allowing people from Africa to come here. Being here and involved in the process directly with lawyer, and access to the immigration office, etc, would help a lot.