Poor service but rich dignity

I have worst experience with Legacy Motors group BMW Menlyn, Pretoria. My car is out of warranty and gave the car for servicing with 1-2 additional complains which are out of normal serving task. They kept my car for 4 nights as they were very busy. After 4 days they returned my car and forgot to do the servicing. As per the manager - they can NOT do the servicing on 29th Nov because due date is Dec in my car dashboard - what a ridiculous version. I ended up paying a hefty amount of bill as they did diagnosis and failed to find any issue. Need to look for another service centre in the future.