this happened to my with my other car...well kind of.....I got my rear quater panel fixed and repainted....done at a cheap price at a cheap shop.....it looked good coming out of the shop but 5 months down the line it got dull cause they didn't put enough clear coat [ for reference..the base coat paint is cheap...clear coat is where painting gets expensive]

I took it to a detail shop..they sanded and compunded the panel and it shined as if it hand a new coat of clear paint.....it looked good but got dull after a few months...after doing that for a couple times...i was running out of paint to compund....[getting to primer now] so i just took it to a better shop and repainted

Bottom line...if you payed good money...infact even if you paid cheap....it should at least shine for the moment...but if your saying you took it out of the shop DULL..then thats a problem

I'd just thought id share a similar story ....hope you get everything worked out!