C3: Infinite history engine goes out

Hello, I have been driving a C3 with 60hp for almost 5 years. Originally my dream car, but in the meantime I would like to plug the car into the scrap press. Since I have it, the engine goes off again and again, sometimes the motor lamp lights up, sometimes only the battery indicator. Mostly when driving slowly, if I turn towards a crossroad or to a red traffic light, while switching down. But once it also occurred at 130 on the highway. During the warranty period I was therefore more After the warranty had expired, the car was several times in a free workshop, today for the last time, since the car ran out the day before yesterday on 2-3 kilometers short distance 5x!. Just came the call from the workshop, that nothing was found and one is at the end with the Latin. If it only runs out once, I ignore that now, but 5x in a row? I am surprised by the fact that no one has hit me at the back, as often as the pa There is no Citroenwerkstatt here in the village, I have had bad experiences with the nearest one. (Unfriendly, car got dirty back.) So the “next” workshop would be a long way away and I don’t want to go there again if it just means nothing again. And in the workshop, of course, the car never makes problems. Does anyone have an idea what the cause might be? V iele Greetings Manuela