It appears you're located in Maryland. I don't know how close you are to Timonium Md.
You might try Roy Fields Auto Service in that city. Lot's of folks on this and other MB WEB sites have praised his skills. Their phone number is 410-252-4101. Roy Fields could assess your problem. With this in hand, you could then approach the dealer and have him do what he didn't to right the first time around.