Battery discharge

Hello, someone already had the experience that the battery has simply discharged itself? With us this happened now since January for the fifth time. Within 48 hours without movement the battery is empty. Partially, the car can not even be opened. Audi has only renewed the largest target breaking point and built us a new battery. But the battery was not. Had the car 3 weeks in the workshop to trade fair: result: No consumer found! Already got the ingenious tip, we s or: if maybe we left the interior lighting on. We didn’t say anything about that then… Our station wagon is of course also spinning, so far at the operating temperature (too high) and the display has every now and then line dropouts! Can this be the cause?? Did they not have to get that out somehow??? Well, maybe someone knows the problem and knows the solution Until then Greetings Wortis