Why Isn't Valieva Kicked Out Of The Olympics?

It really shouldn't be this hard to understand but if a sportsman is caught taking a banned drug, they are kicked out of the Olympics so why Russian skater, Kamila Valieva, has been allowed to continue competing after failing a test for banned drug Trimetazidine i just don't understand.
The 15-year-old Russian figure skater is being allowed to continue competinbg at Beijing 2022 despite testing positive for banned angina drug trimetazidine and two others which are not currently banned.
The substances are all used for enhancing performance by increasing endurance and reducing fatigue so she has an advantage over the other competitors and she currently leads the race for Gold and is the favourite to win although the The International Olympic Committee have said that is she does win, there will be no medal ceremony
The reason put forward by the Russians is that her positive drugs test was due to contamination with her
grandad's medicine, possibly she used a glass that he had been drinking from and although i am no doctor, that sounds highly suspicious.
It is the other Olympians i feel sorry for, they know that they are not competing on a level playing field and that the young girl currently beating them has failed a drug test and has had an artificial advantage over them regardless of how the trimetazidine got into her body.
This all comes despite Russia being banned from the Olympics for wholesale drug abuse and Russian athletes competing under the Russian Olympic Committee flag but the other skaters would be justified in refusing to compete against her because it isn't fair to them after years of dedication, hard work and endless days of training to watch someone who has cheated their way to victory beat them.