Disgusting

I bought a Brand new BMW GS 310, it is my 2nd 310 , my reason for it. Unfortunately I didnt test ride it as I purchased it from a out of town dealer. After riding the bike I heard this whining sound when using the motor to slow down, took it in for its 1000 km service and asked them to test it bot mechanic and Foreman said it wasnt right, long story short nothing is being done I am sitting with a brand new bike that I will never ride and im paying for but it will be the last BMW I will ever buy.