If you are having problems with your gearbox, and clutch as delivered from the carrier, those boys were joyriding it around.
There was a problem like that with MatG from a car that was sold out of AZ. The shipping guys damaged the car, burnt the clutch, and destroyed the ZF Synchros. It cost 10s of thousands to fix.
You need to get with your carrier IMMEDIATELY and file a claim.
Don't drive it any more - it weakens your claim.