Kick (someone or something) down the ladder American British informal
To exclude or pull someone or something into a lower position or status to prevent them from having the same success as you, particularly one who has helped you
After becoming the Deputy Director, he has kicked his old friends down the ladder.
Many guys forget others right after obtaining wealth and reputation, they easily kick their advocates down the ladder.
Although I have instructed him in writing scientific research, he kicked me down the ladder by ignoring my begging.
The verb "kick" should be conjugated according to its tense.
It is impossible for a person to change his or her innate or fundamental nature.
He said he would quit alcohol, but he still can't desist from drinking. Once an alcoholic, always an alcoholic.