had the radiator flush in august 0f 2013 in dec of 2013 when i turned on the heater the driver side throws cold air and the passenger side throws warm air. what did firestone do wrong

Sounds like you have a blend or mode door actuator issue. Very common problem with these trucks. Might even be one of the doors them selves broke.

And this problem would not have been caused by a simple system flush. Also I would not advise mixing the anti-freezes. Stick to the same as what came with truck when new.

www.youtube.com/watch?v=KAclL84Qq8E --- this may help you figure out what is actually wrong with yours.

dont mix coolants, they will gel up and not flow through the engine and rad properly ( mechanic told me, havent tried it myself) i dont like the orange coolant, its very harsh on seals and gaskets, it disolved my o-rings in 1 year on a part i replaced, lost my coolant, thermometer didnt display correctly, blew my engine. if you are doing any work, or flushing it, i would replace it with green.