Hi Mark, if the description is the same as mine then bring the bike right back. My dealer was Wollaston BMW Northants who were very good. There was no fuss at all. In fact, they sold 'my bike' with its new powertrain fitted immediately
Again, if there is a bacon slicer noise (shwishhh shwissshhh shwishhh) road speed sensitive (not engine speed related) that's it. They know of the issue. Get your money back.
I will buy another one - but I'll wait until next year when the bugs are gone. Good luck - let me know if you want to talk and we can arrange something.