Everybody askes that. Yes, I know how to operator a dryer too. And mine leaves the clothes wet too. After a diligent effort to make the damn things work, they still suck.
The duct was jammed full of lint. So, no air was flowing out. The dryer had a safety interlock that disabled the heater. This is why the clothes took so long to dry. It is also why we didn't start a fire and burn down the house.
Now we clean the ducts every 18 months and the dryer works great.