New brake pads, lots of problems

[petekav]

Had my rears discs and pads replaced today.
Collected the car, and as soon as I got 2 yards down the road I realised it didn't feel right - brake pedal feel had totally gone!
When the pedal was depressed it went almost right down to the floor before "engaging", previously this was <2".
I took it right back to the garage and asked them had they forgotten to bleed the brakes! They claimed they had, and I could see fluid around the filler cap which suggests they had at least removed the cap.
The guy drove it around the car park and claimed they were just bedding in. I wasn't convinced. He told me that it would take at least 15 miles and then pedal feel would return.
Stopping power is greatly diminished, and pumping the brakes seems to help. To me this would point directly to them needing re-bleeding.

Any thoughts?

Thanks, Pete.