Looking at the situation from both a legal and spiritual perspective:

What should you do about continuing to do business with Don?
If you should elect to stop doing business with Don, what legal causes of action might he bring against your company, what damages or remedies might he seek, and what legal defenses might your company have?

In connection with this assignment you may want to research the following legal concepts and incorporate what you find in your DB response if you consider them relevant:
Covenants of good faith and fair dealing
Minor’s capacity to contract
Fraud in the execution of a contract
An employee’s capacity to bind a company by contract
Section 2-306 of the Uniform Commercial Code
Implied contracts
Promissory Estoppel
Custom and practice between merchants
Any other legal concepts you believe may be relevant

You may also want to look at:
Sons of Thunder, Inc. v. Borden, Inc., 148 N.J. 396 (1997)
Jenkins, Sarah Howard, Symposium: Contracting out of the Uniform Commercial Code: Contracting out of Article 2: Minimizing the obligation of Performance & Liability for Breach,40 Loy. L.A. L. Rev. 401 (Fall, 2006).