Dell 3100cn printer - Service Centers

I just spent more than $400 for new print cartridges. When I installed the black one, and printed 4 sheets, I got a message to relace black toner!

I installed the second of the 2 new ones I purchased, and got the same message.

Apparently I have a tech. problem.

My printer is out of warranty.

Does anyone know where I can take it for repairs?  Does Dell have authorized service centers.