Been thinking about this one. Logically, it can't be usage as it is too new to wear out. It can't be vandalism by the car being unattended/unlocked as why would someone damage the belts and not damage other stuff as well?
That now leaves two definite options. Either the owner has damaged them either deliberately or accidentally, or, as some have suggested, someone in the factory has fitted them for whatever reason. Was it because lack of parts? Could it have been a worker(s) with a gripe? Why didn't the garage find it on their PDI?
For what reason would the belts be self damaged when the owner loves the car? If the car is on finance he looses out big time. If he has bought the car outright, he looses out big time. It can only mean that the car was supplied faulty by the garage.
In my view this is as serious as it gets and agree that this should go up the highest in the MG company as this could be disasterous for them if they deny any wrongdoing. Wow, I am shocked.
Went straight out to check my MG4 Short Range [bought November 22] and all is well. Very good drive, avraging 4.1, infotainment flakey.