What to do when client Abuse you and threats you with bad feedback, if you don't agree with him ?

[snausher]

What should I do If I don't want to work with a client, because of his attitude, he is abusive and give threats for bad feedback, I have told him that I can not work with him, so what is the solution for me ? 
he will give me a bad feedback and will ruin my profile. 😕 

[g_vasilevski]

Hi Salman,

Could you please reach out to me via PM (click on my name) and share more details with me so that our team can investigate this further? Thank you.