Dishonesty and non-payment

After my cancellation of a paid for course, done on 20 December 2015, I have still not received my refund. Even after twice having received a promise to pay and a formal credit note. I have received no replies to any of my communication unless it was in the owner's favour to respond. She refuses, however, to respond to any of my proof of payment requests. What a major disappointment that a company whom teaches young adults in a profession and distributes products to other companies can have such low business ethics. Wonder what they have done under your nose?