I have a question about 'never mind' and sth.
Q1. Is 'never mind' used right in the situation 1? If not, would tell me what A could say?

Situation 1

A : Would you help me with this homework now?
B : I'm busy now. I'll do later. (But it seems that B's work is not important enough to refuse A)
Few hours later.
B : What's your homework? Let me help you.
A : ( *Never mind! ) (A was disappointed and angry at B's inconsideration. So A DOESN'T WANT B's help anymore.)

Q2. Would you tell me what B in the situation 2 probably says?

Situation 2
A : I don't know what I did wrong?
B : Really?
A : No! I don't! Don't blame me because of your fault.

But later, A realize that it was his fault and try to apologize to B.
A : I'm sorry.
B : ( ? ) ( B is still angry at A, and DOESN'T WANT to accept A's apology now.)

Question

I have a question about 'never mind' and sth.
Q1. Is 'never mind' used right in the situation 1? If not, would tell me what A could say?

Situation 1 

A : Would you help me with this homework now? 
B : I'm busy now. I'll do later. (But it seems that B's work is not important enough to refuse A) 
Few hours later. 
B : What's your homework? Let me help you. 
A : ( *Never mind! )     (A was disappointed and angry at B's inconsideration. So A DOESN'T WANT B's help anymore.) 


Q2. Would you tell me what B in the situation 2 probably says?

Situation 2 
A : I don't know what I did wrong? 
B : Really? 
A : No! I don't! Don't blame me because of your fault. 

But later, A realize that it was his fault and try to apologize to B. 
A : I'm sorry. 
B : (      ?        ) ( B is still angry at A, and DOESN'T WANT to accept A's apology now.)

Answer

Thank you for your answers!

Answer

Q1.  Yes; "never mind" is used correctly in that conversation.

Q2.  This isn't necessarily the "proper" way to answer, but a common response for B might be "Whatever."

Answer

In situation 1 it is suitable for A to say 'Nevermind'.

In situation 2 B could reply :

"Don't worry, it is ok ,I think I can manage on my own."

This way B is polite and composed and gives a good reason why he doesn't need further help from A. He will have to act like  accepting A's  apology at least verbally, yet  his tone will show that he is somehow still angry.