At first appearance it does look like ich, but with the ich parasites life cycle, even with no treatment, you would expect it to clear up in under a week as the parasite ends its feeding stage and drops off the fish to reproduce in the substrate. If the parasite isnt then treated during the freeswimming stage it would reinfect fish and you would again see the spots.
From the photo it looks like the spots are on the angelfishes fin rays. So they could be fin ray fractures which is caused by damage to the cartilaginous fin rays which produces a localised swelling. In my experience this doesnt heal completely. Its fairly common in angelfish, the angelfish in my avatar has 1 such spot, ive seen other angelfish with several such spots. If that's what yours are, ive never seen a case as severe as that and would be the result of quite severe damage.
There are diseases other than ich that can cause ich like spots too.
You bought it like that? Or that happened shortly after you bought it?