For school refusal, maybe parents could try to understand more of the reasons behind the refusal then you can work with your child on those underlying reasons. Some questions that might help to clarify are:

1. When did this start? Were there any triggers?
2. Are there any other information that you can gather from teachers at school or your helper at home as to the experiences of your child?

I think firstly parents have to think about what was difficult for them when the child talks back. Children at that age is gaining autonomy and control over their decisions and actions and it is normal for them to want to express their own opinions and thoughts. Probably parent would have to communicate with the child their thoughts and feelings after they understood better what was difficult for them when the child talks back.