This article being from last year proves again that WADA and the IAAF are not at all serious about policing the sport. Montsho was a doper and Amos seems to be one as well, three missed tests and concern that he wouldn't pass:
"It is not the first time the 2012 Olympic silver medalist absconded from the test in fact, Masalila has revealed that it was the third time Amos failed to honor the call, and this time around the agency seems to be ready to crack the whip. Part of the letter states the athlete could suffer consequences.
Sources close to the athlete have also revealed that Amos has confessed the incident to them. ’’It appears that he was not prepared, and after receiving the call from WADA notifying him about their intentions he immediately fled to Botswana to avoid embarrassment because it appears he is not sure about his status,’’ one of the sources revealed.
Masalila has also gone on to say that their efforts to speak to and guide the athlete have proved futile as the 21 year old is ‘ignorant’. “This boy is overwhelmed by childish behavior and this may ruin his future because he is just ignorant and refuses advices.’’"