You have a lot of issues in your concern. I will address the breach of contract
If you are spending a lot of money due to their negligence and incompetence, then you can remove the fees from their pay. For example, let's assume they earned $1000.00 (that you agreed to) for fixing your plumbing, and that was done in an incorrect, dangerous, or negligent fashion. To fix their mistakes, you went ahead and hired a plumber for $800.00. When you pay them, you only owe them $200.00 because the value of their work is based on what you had to do to fix it. On the other hand, if you had to pay $1,500.00 to fix their mistakes, then you can bring suit against them for the extra $500.00 because you would not have had those damages but for their negligence and incompetence.
In other words, any extra fees/costs that you had, you can assess it against their final bill.
As for their alleged criminal activity (thefts, pornography, etc...) I suggest you file a formal criminal complaint. It may be a good idea to proactively contact your teacher's union in strict confidentiality, and speak to one of their counsel. Explain the problem with the pornography and ask them as to how best to proceed. Because attorneys are governed by a strict code of confidentiality, anything you say to them will be protected. If, somehow, that information leaks out, you can sue the attorney for damages, as well as go through the local bar
to have him be censured, suspended, or even dis-barred--so most attorneys will not take the chance.
I hope I was able to answer your questions,
Dimitry Alexander Kaplun, Esq.