First things first, WELCOME to the real world. You will have fun, and your stay will be enjoyable, and best of all, EVENTUALLY, your car will get fixed, ERNJOY.

I have NO IDEA where in this huge world you are, so you might want to update that little bit to helps us all. These cars varied quite a bit from one market to another, and we Aussies are just plain out there in the sticks at any time.

I can see no relevence to using the a/c to increased smells of fuel, based on the work you have had done, other than the fact that the fuel returning to the tank will be hotter and giving off more fumes, maybe. A fuel weep under the bonnet would answer that a little better, but not from the fuel tank area.

I have just done my fuel pump, so the brain is still kinda fresh as to what is what back there, at least for Aussie cars.

There is a vent hose (plastic) on the LH side of the tank, with a plastic coupling attachment thingy, and is a bit of a pain to refit correctly. This plastic pipe is tucked in between the wheel arch and the tank (real tight squeeze) and it is very easily caught and damaged when sliding the tank back into place.

The "top lid" of the tank is removed to access the pump, and a NEW seal should be fitted, and that large locking ring should have the "slopes" lubed a little bit to make refitting a tad easier, and that same lid has another vent hose attached with a clamp.

I dont reckon you got a fuel leak as such, you have a fuel fume issue, and that will be found IF the guy concerned backtraces his steps VERY carefully, and that may require you twisting his arm considerably, coz it did not smell prior to pump replacement, so he has done something unwell.

The 2 quick connect steel pipes under the car may be weeping, but highly unlikely in my opinion.

The fuel tank sender seal may be weeping, IF he had it out, but as there is no need, he possibly did not touch it??.

Good luck.