Automatic Transmission Torque Converter problems of the 2003 Mercedes Benz 320

I purchased a mercedes-benz e320 in June 2003 and have continued to have an issue involving uncontrolled acceleration and speed "surges" since September 2003. The condition seems to be more prevalent when the vehicle is approaching low speeds or in a downhill plane the dealership has attempted to repair the vehicle during five (5) service appointments and has acknowledged they are aware of the uncontrolled power, or acceleration, fluctuations. They have attempted to repair the vehicle using m-b advice; without success. M-b representatives have acknowledged this condition exists as well; but, that it is not a "warrantable defect. " this "surging" has further developed into "bucking" on several occcasions causing loss of control of the vehicle. This condition appears to be similar to other complaints filed with the NHTSA regarding the e320 where the torque converter lock up is described. I do believe it is a safety hazard due to the inability to control the power / speed fluctuations of the vehicle.