Chas Roberts Air Conditioning

Brand new build lived in the house for two years and there has been no problems with heating and cooling. So no need to do anything and look at anything then all of a sudden thermostat his dead and nothing working. I go up to trouble shoot an in the air handler is a 3 Amp fuse that chase Robert's put in. A tech from chase Robert's comes out says he pull on the thermostat wires that went to the ac unit because sometimes they get pinch and instead of putting a 3 Amp fuse back he put a 5 Amp fuse. This is a little suspicious in my book. And the charged me 85 dollars why did they not put a 5 Amp fuse in the first place and if the wires get pinch why don't they do the do diligence to pull back on the wire to relieve pressure. Are they doing this to get an extra service fee that take 5 min to repair. Or is their repairman just that lazy to do the job right make it work with a 3 Amp fuse