2003 Tacoma TRD overheating

I have a 2003 Tacoma TRD that has always ran flawlessly. I took it in for the recommended 100k service of water-pump, thermostat, timing belt and serpentine belts from a mechanic shop and ever since the 100k service the engine has been running hot. Over the last year I have added 5k miles and have taken it back 4 different times and was told that it was fixed each of the 4 times with no success. It still gets hot. At this point I have lost faith in the shop as they say I may have a blown gasket now. My truck was flawless up until this service was done. They also have changed the radiator and flushed the block. This is not my primary vehicle therefore I don't use it a lot.

Any suggestions on what could be going on?