Advice on body work

Good grief! I've seen bad paint and body work, but that's beyond awful. Unfortunately, fixing that mess is going to cost more than the hacked repair did. This is probably going be an expensive lesson learned.

BTW: Some (uninformed) people think MAACO does great work.

 

A wrecked vehicle with good quality repair and paint will be very hard to distinguish from one that's not wrecked. Unfortunately, I would never believe that yours was nothing more than just a corner taillight.
At this point, fixing that gap is the least of your problems and won't fix that substandard paint job.
Sorry OP, delaying the repair and spending the money from the initial insurance payout painted you in a corner.

 

Your F@#$ed. If you want it to look good take it to a reputable body shop and have the mess repaired. It will look good and last a long time. This repair is destined for nothing but bubbling up in about 8 months from now.
Tell MAACO your taking them to court for the final cost of the repair and good luck with that.

 

As the others have mentioned, you kind of put yourself in a jam by going to Macco so in the end it's going to cost even more to get it fixed correctly. My advice, not knowing how much the total cost is, is to accept that you got what you paid for. If you were able to drive it around before when it was beat up, you should be OK with it looking somewhat decent. There's not much you can do with the paint. If there was enough clear on there, they could wet sand it to minimize all that orange peel. However, I would assume it's a single stage paint that's probably laid on very thin. If you don't want to dumb anymore money into the paint, leave it as-is. You can find a paintless dent removal person to see if they can pull the bedside out to make it line up better with the tail light. This is probably the most cost effective route.

 

Hope you filmed the manager's tirade.