Untrustworthy accordion dealer

At the Cotati Accordion Festival Martin Hergt told me the accordion he was selling retailed for $5000 but he would sell me a used one for $4000. I purchased the accordion but then discovered the manufacturer's suggested new retail price is actually $3295-3052. Since I had a few payments left on the accordion, I tried to contact Martin via post and email for an explanation. I asked that he not charge my account until he explained why the prices he told me were so far from the truth. He has not contacted me but has continued to charge my account for the balance. I realize people should do their homework (buyer beware), and I'm sorry I trusted this salesman. I would not recommend purchasing accordions from this business.