I cant find anything online and even though you have several Porsche dealerships (some countries have only 1 or 2) the reviews are mixed . The best one with the most positive reviews seem to say that they sometimes get the repair wrong and are expensive . My suggestion is to find that one technician (usually the shop foreman) who can fix it correctly . No matter how I imagine it I think it will cost you money to fix the car UNTIL you find a private mechanic . They probably are not common but through other Porsche owners in your area you might learn. In my searches I did find a Porsche club in Pannonia (spelling) . I could not open the facebook page as I dont have facebook but its car gatherings and clubs which have long time Porsche guys who can advise .
Good luck.