Auto Body question for pro

Amj2020

I recently installed a full kit on my car and the rear amuse bumper was smooth when I handed it to them raw. Once I got it back painted, around the tail lights, I see what appears to be the contour of fiberglass mesh, not even an orange peel effect, it looks like the mesh...period.

I called the body shop and they kept saying it 'sucked' the paint and crap back into the mesh. The part is FRP but it was smooth as a babies *** when I handed it to them. With all the money I paid shouldn't they have smoothed it out and block sanded it until it was perfect? I never knew it could degrade all the way back to the fiberglass sheet from applying paint, this does not make logical sense to me.

Can this be repaired by anything other than a repaint?
I want to have knowledge from pros when I go back there so that I know what I am saying rather than pontificating at what may be true.
Thanks in advance!

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2012 Magnetic Black 370z | Fast Intentions CBE | Stillen G3 | Motordyne ART | H&R Coilovers | Work Emotion | Fujimura | Uprev | Amuse| GT-R Start