Ford mondeo gear selection?

When driving around a roundabout, I changed from 3rd into 2nd gear, there was clonk sound and then the engine was revving but no gears. I tried to put it into all the other gears subsequently but it would engage any of them. No previous problems with getting into gears before. Havent had the car long. All the garages I have rang say I will have to change DMF plus clutch etc. Very costly. Towed the car home after that. I have also tried starting the car in first gear and it doesnot surge forward. Has the clutch gone, just like that. Can anyone help