I'm not a complainer… but even I think that you should complain (nicely). It's been a month, but do it anyway.
Before checking the fuses, if you must do anything but complain, I suggest you get the plastic panels off that expose the cabin filter and take a good look yourself. Your instinct regarding the wiring might be correct.
If the filter-guy was a grunt, then he might have pulled on the wires and pulled one out of the plug without noticing. He might also have left the ignition on and pulled those wires, but I wonder why there are no error codes - perhaps not when it's just the A/C system.
Remove the plugs yourself, then plug them back in, making sure each wire/pin is inserted all the way into the socket/plug.
In my experience, fuses rarely blow, even when messing around with connectors on a car with the ignition on.
