Worst gearbox I've ever known

HONDA CIVIC HATCHBACK 2015-onwards

Awful gearbox. Shifting from 3rd to 2nd gear is a complete lottery, sometimes it will and sometimes it won't! Took the car to the dealership to be checked whilst under warranty only to be told that it was normal for this model. Also 1.8 petrol model gives very poor performance in terms of accelleration, overtaking the vehicle in front requires very serious consideration, again told this is normal. Quite possibly the most disappointing car I've ever owned.