Horrible service

I need to change ownership of my account to the new owner .I sold my car in January ,called the call Centre number on 15 January to inform them that the new owner is willing to take over , the consultant promised to call the new owner and send him the relevant forms. To date we are still waiting for this call, i emailed the customer care on 15 January and no responce to date . The call center has 1 number *** and has 2 option 1) Repairs and 2) Installation , and there is no answer on both options