wouldn't have as much work.
I've seen the exact same problem many times over on Toyota,caused by jump starting incorrectly or hooking batteries backwards.
I don't know much about Mazda fuse locations but I am a Toyota master tech and can give you a general idea where to look.From what you describe,I wouldn't trust them to screw in a light bulb,much less trouble shoot the problem they caused.
Yes,putting the battery in backwards WILL(not maybe)cause damage.If you're lucky,it's just a few blown fuses and not damage to one of the car's computers.
Computer codes can't be read because the fuse controlling the diagnostic circuit blew when the battery was installed.Just hope the spike of reverse polarity didn't reach the computer itself.
There is more than one fuse block location,there should be one next to the battery with a bunch of fuses and high amp fusible links in it.There should be another either in the left side kick panel or next to the steering column behind the panel.
There are no short cuts to this,someone who knows what they're doing has to get in there and check every fuse in the car with a test light or voltmeter,at the most it should take about an hour to diagnose correctly.
Had my battery replaced yesterday in a 2000 Mazda Protege, at a car parts store. Initially, they put the battery in backward, and it sparked when they tried to connect the terminals. Afterward, the following don't work in my car: radio/clock, key/light alarms, dome light. ALL were working fine before. Also, the check engine light came on, but NOTHING shows when you try to check the code. There may be more problems I haven't discovered yet. The store manager checked the battery and fuses, says all are fine, and he has no idea what may have caused those malfunctions or why he also was unable to read any check engine codes. Any idea what might be wrong?