How do you know it's a data cable?
First, sack the person who did it.
If it's a CAT type ethernet cable, standard sheath and cores, it probably has had it.
You could spend a lot of time trying to remove it and then find it's damaged.
I would cut my losses and chop it off both sides of the wall.
Make up new connectors, RJ 45 for CAT cables and drill a new hole, line it with conduit and put a new section in.
If it's armoured, then you might be able to chisel out around it to release it.
I'm afraid that without more information than "data cable", most of this is guesswork.