The first and second question are completely unrelated. Ignoring means not giving attention at all. This one is serious. You have to act like you don't give even a sinlge fuck. But incase he/she tries to talk to you, act like nothing happened and talk to them. Never show them your frustration and anger 'cause that is the fuel for their hatred and disrespect. The second one is much lighter, the problem with us people is that no argument wins our opinion. Even if in reality the other person came up with strong evidence. So, try to explain to them one's. If they keep on interrupting while you talking, stop. Let them finish what they have till the end(till the end). Then say nothing but okay, we will talk later or tomorrow. Everything we talk and argue about while in anger emanates from emotion. It is not rational at all. So it is better to postpone things. If this person keeps doing this like forever, you better walk away. Doesn't worth your time. You need freedom(mental one)