In general, in Islam, one should avoid breaking ties with one's family unless there is a serious and overriding reason (such as fear for one's life). However, whether one wishes to maintain a close relationship or a more distant relationship is a personal choice.
I don't know the details of this situation. I would surmise that in most cases, if parents break ties with their children on account of their child's poor academic performance, it is due to (a) other issues, not just academics, (b) an attempt to motivate the child to do better by "punishing" them, or (c) a projection of their own psychological issues onto the child.
Anyway, all the child can do is try to be polite and respectful, try to avoid arguments, and keep the door open in case they wish to resume communication.
If a young person is not doing well in academics, and has tried various ways to improve but has not succeeded, it is worth considering other options such as vocational school or going into business. Everyone has their own skills and talents. There are a lot of jobs that are not related to academics (such as being a chef or plumber) which pay well and are necessary jobs for society, even if the parents' dream is for their child to do something else.