It is a valid point that the quoted weight some makers give is the weight of the bat before it is 'dressed' (stickers, grip, toe guard, anti scuff etc) which can add 2-4 ounces dependant on grip type. I know that H4L produce a bat that when dressed, weighs the desired weight (In my case, I requested 2'8, it weighed 2'5 undressed and bang on 2'8 when stickered).
However another consideration is your scales. Most kitchen scales aren't terribly accurate (fine for measuring ingredients as the error is a constant one, you still end up with the same ratio of ingredients) but for weighing bats they are not ideal. I've seen bats sold on the forum as, for example, 2'8 and when the new owner weighs it, they complain because their scales read 2'10.
The best thing to do is forget what the scales say and decide if the bat is too heavy by swinging it, comparing it to known bats that you know are not too heavy and go from there. If you still think it is too heavy, it will be worth trying to access some scales that you know are accurate before you contact MH.