2003 320e sos tele comunication malfuction - 2005 Mercedes-Benz Mercedes Benz E320 Cdi

Hi i have mercedes e320 wagon problem is shifting gear
i go to mackanic and he said your gear is not ok need to change so i buy used and he fix **** problem was still there then he said your computer is not ok then again i try searching computer and atleast i find he change it and reset every thing **** still same problem
then he start testing wires **** he cant get saloution and in the end i took my car and go to another macanic
then this guy said that your gear noumber is not same so need same noumber gear
and i buy second used gear and he change it nothing hapen
then he bring some computer and try **** nothing hapen and he can,t get to saloution
then he said need shifter i buy shifter **** nothing hapen and same problem and don,t get saloution please try to help me soon
thanks