@Christoph Kirst
I was the other mechanic in the store and think there should be a comment from our side to what you wrote. Our mechanic offered you a new tire because yours was in a very poor condition. We always offer our customers a new tire when we consider it unsafe to ride. When you declined the new tire, we fixed your flat and installed back your old tire. We made clear that we think your tire is unsafe, but never pushed you into buying something you didn’t want.