To be honest, no one can recommend a delivery service with a 100% delivery positive rating.
All services / couriers will lose items from time to time. Human error, computer error ? It will happen.
I use Royal Mail, and must admit reading from other sellers here, the rate of loses they have experienced using Yodel or Evri, I'm sticking to RM, for me in 13 years , they may have lost only a couple .
As said not one service can, or promise to, deliver with 100% precision.
@ioili_27