I recently bought this mixer from Amazon: The first unit arrived broken. It would not spin, although the motor worked. I contacted the distributor and they sent a replacement. The current unit works, but I see that the steel blades of the head are touching the bottom of the steel bowl. Normally, these mixers are adjustable, but this one does not reveal a screw in the middle when the head tilts back. So I am assuming it is not adjustable. I talked with their support person and was told that it is normal for the head to touch the bowl and that it will not result in scratching. Is this true or should I expect to find heavily worn heads + stainless steel in my food?