If it's being done under warrenty then I would leave it alone until you've spoken to them.
Remind them of your instructions and inform them that they have only done a botch job, not a repair, and give them the chance to fix it.
Even contact Land Rover Customer Service if it's a Land Rover fanchised dealer and tell them about the problem and the quality of work carried out.
Don't get someone else to do the job before the dealer has give the go-ahead otherwise you will, most likely, be stuck with the repair bill and no warrenty on it for any future problems!
Oh, and if the headlining is now stained because of their workmanship then get them to replace that as well!!
