Please could you tell me- what are the punishments for disobeying/ disrespecting your teachers?

Praise be to Allah, the Lord of the World; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

Compilations of Muslim scholars (May Allah's Mercy be upon them) are filled with knowledge that urges students to respect and honor teachers.
As a rule, every Muslim is required to be of good character and noble manners in general. But, good character is most required with teachers and scholars. Moreover, contempt and making little of others is of very bad character. The Prophet (Sallallahu Alaihi wa Sallam) banned such an evil action in more than one Hadith. He (Sallallahu Alaihi wa Sallam) said: "A Muslim is the brother of a Muslim: He does not wrong him, nor does he disappoint him, no does he scorn him". [Reported by Imam Muslim]
If Muslims, in general, are required to fraternize, live peacefully together and to be in harmony with one another, teachers are more deserving of good treatment. What bad character it is for the one who scorns teachers and is enlisted with those who wrong and disappoint a Muslim! Thus, it become clear that it is Haram to scorn, wrong or disappoint a Muslim, and one who does such will be punished Here in Here-after.
Allah knows best.