Shocking Service and no communication

Car has been in for repair for 6 months now, this is a second time that they have my Audi for over 6 months and fail to fix the issue. Recent visit to their premises i was told the owners are not there but the one was he was hiding away because i did see him on my arrival in his smaller workshop. Their service is appalling and lack of communication shocking, false promises every week. I would never use them again its only because they sold me the car that i do use them.