Originally Posted by Jon651

Bad starter or starter solenoid was my first guess. Next would be a short to ground somewhere along the power wire from the starter to the battery that doesn't get energized until you turn the key. If the shop is claiming it is drawing too many amps it might be a bad ground strap (unlikely but still worth checking). The problem will be that all the connections will look good unless you get super lucky and find something burnt. It's going to take someone who is good with a test meter to track down the electrical pathway between the fuse and the starter, but just know that Mazdas are notoriously difficult to work on, especially finding electrical faults.