Corolla 96 Timing Belt queries.?

Hi, I have a Corolla 96 milege 85000. I went to EZLube to get the oil change and the mechanic told me that the timing belt needed to be changed and will cost $200. He changed three belts(engine, alternator and something else) within 15 minutes without opening anything and from outside. I have read somewhere that changing the timing belt takes lot of time and someting over the engine needs to be opened and also it costs a lot around $500-600. I am worrying whether he has done the right thing or it was not changing the timing belt but something else. Thanks in advance for your help.
Corolla 96 Timing Belt queries.?
my answer is try to check it out first on auto repair shop....dude