Wanted to hand in my cell phone to repair / replac...

Wanted to hand in my cell phone to repair / replace the battery and because it has a few scratches on the edge, the guy said the guarantee was not valid. After I told him vigorously that there is no scientific study that proves a causality between scratch and battery defect, that we are in a constitutional state, that the guarantee is valid and whether he seriously feels that I would tolerate it, he had to briefly for consultation with his colleague. When he came back he apologized for his "misinformation" and from now on everything worked perfectly. There was also a free replacement device and the repaired device was sent to me free of charge and I even got a stamped box with which I could send the device back. If this stupid behavior hadn't been in the beginning, there would have been two more stars.