Still overheaating after having water pump replaced

if you didnt get a new thermostat when the other work was done then try that. it sounds like you might have some air in your system that needs bled. there are some good vids on youtube on how to bleed your cooling system of air.

Like mikeatpriestlake says, BLEED the air out of the system. Locate the bleeder valves for your make/model. It can take some time to get all the air out. (expect some frustration!)