ripped off or not?

[Evo141n]

I've a volvo v50 with a sheared off bleed nipple on one of the rear callipers. While in for a service last week the garage said I needed a full brake fluid change. However looking under the car today the sheared nipple is still inplace!

I'm sure you cant do a full brake fuild change without removing and bleeding this rear calliper.
Or would the garage have a way. (I doubt it).

I'm looking to create merry hell down at the garage on Monday for ripping me off.
Unless some one can suggest that the garage could have done the work?

[Evo141n]

Garage say they disconected the brake pipe union from the caliper, then used a machine to bleed. Not 100% sure but they seem to say they revoved the old fuild from the caliper and replaced it before replacing the union? :/