Engen cordonia worse Engen to assist

Double billed and they refusing to refund me the one payment even after printing out a statement and evening willing to show that the money hasn't been repaid by my bank. They making it very difficult to get a refund even after I have proof it went off and hasn't been reversed. Manager was helpfull but the owner seemed very eager not to just pay out after it was their card machine that made the mistake in the first placeo