OK, I am a business owner that accepts credit card payments, so I look at this from both sides, and I agree with Apostle basically.
You purchased material, and were not satisfied with it, yet you retain it in your possesion. You must either return the material, or pay for it. He has the right to bring a complaint against you for this.
Mike may be the person at his local warehouse, he may not buy direct from Rancho, but rather from one of their master distributors.
The second charge may not be his doing, it may actually be a reversal of the credit car companies decision based on your refusal to return the merchandise. When you initially protest a charge, the credit card company will immediatly syphon the amount in question out of the merchants account. This amount is eventually awarded to whomever they agree with.
If he did run the charge a second time on his own, then the credit card company can determine from their records if the card # was entered by hand, or swiped in. They will request a copy of both the sales recipt, and a signed copy of the card slip. His failure to produce either will cause them to find against him. It will be interesting if your signiture is forged on the 2nd recipt.
What should you do?
You need to decide if you wish to keep the material. If so, do nothing, you are even.
If not, you need to return it immediatly, and have the credit card company reverse the ssecond charge. I would also ask the credit card company to issue you a replacement card with a different number to prevent any further issues with this person, or any other who may have been given this number.
John C.