Just replaced thermostat and car is still overheating?

Try the bleeding procedures again and see if it helps.

Prior to replacement of the thermostat, was the engine overheating?
Is the new thermostat of the correct rating?

Try running the engine with thermostat removed and see if problem goes away.
Get a test kit for checking presence of carbon in coolant to verify if the head gasket has a problem.
Do you have coolant losses issues before rreplacement of the thermostat?

After he work done, when engine is cold, was the radiator coolant level checked and was it ok?
Do you still have coolant losses issues?
Have you performed the bleeding as I suggested?
Is there any difference in the situation?

Head gasket leaks would not be visible, if it is, the engine would not be able to run as the damage is very bad and would result in loss of compression. Check if the engine oil has traces of coolant. A test kit would confirm the presence of carbon in the cooling system indicating a bad head.

With coolant filled correctly and radiator cap closed, try revving the engine and checking if coolant is bubbling up at the reservoir.