Air in clutch line 2004 Chevy Cavalier

Had a local shop put new clutch, clutch master cylinder and slve cylinder in my 2004 Chevrolet Cavalier.  The work went quickly, but they spent 2 days trying to bleed the system, saying it was very tricky.

Now, after one day, clutch is going to floor, and must be pumped to even get the car in gear, then it still rolls slowly while clutch is fully depressed.

Is it really that difficult to bleed the clutch in this car? Or is there some trick that they are missing?

Any help is greatly appreciated!

Thanks!