I have been through this situation before. Now the client is my best client. All that you need to do when he is abusing is to never interpt them. Let them complete their full statement or sentence. Genuinely say sorry for the mistakes done and for the things you are not at fault, say that you will try to do better than that. Try to bring clever humor in your conversation. Such people always have lot of pride, handle his pride in your favor. Give them better ideas than what they have. Win them through your intelligence. Let them know that you have some good qualities or skills which would improve their business etc. I gave him better content than what he already had. Made him understand why it is better than his content and how it is going to impact his business. Win him through your good work and business sense, little time consuming, but for sure he will start respecting you more and give you more projects. The client who gave me a project for $999 with lot of abuse in the beginning ended up giving me $32k business and now he is my best client and friend. Patience is the key here. Patience, perseverance, and persuasiveness will make you see the light at the end of the tunnel. Please note , if your intuition tells you not to work with such people. Stop work and move away.