Talk to the orthopedic surgeon who did your surgery. It could be that the type of repair done can't restore normal motion and function. This is often the case with AC repairs. If screws, wires, or sutures were used the hardware may give you lots of stability but not as much mobility.

The doctor will be able to assess your joint and possibly take X-rays to find out what's wrong. It's possible nothing else can be done. Perhaps a second surgery is needed to modify the repair.