I put my Logitech MX keyboard in the bag with few other things and one of the keycap broke off. Completely my fault. Since the key mechanism was intact I have told their support what happened and asked if they sell replacement keycaps and got completely new keyboard for free.
Great support but I was left with mixed feelings since I still had almost completely working keyboard and I think the experience would be better if they would send me just the keycap.