Damark abuses access to customers credit cards

I ordered a computer w/monitor and printer from Damark on 3/11/00. The product was received on 4/07/00. The computer was broken, it could not boot up. I phoned customer service and was told to return the products at their expense. I returned the product and cancelled the order. That is when the problem occurred. Damark refused to credit my account for the full amount of the product. When questioned, they claimed that the missing $73.99 was a "membership fee", and was non-refundable. I called my bank to dispute the charge, and was told by my bank that essentially, Damark was entitled to add charges to my Visa credit/debit card, because I had "previously placed an order with the company, establishing a merchant-customer relationship". I asked my bank (Washington Mutual) if it was considered a "legal and ethical practice" for companies to arbitrarily place charges on customers' credit cards, simply because they had the credit card number on file from a previous transaction. The bank's representative 'Debra', replied that yes, this was legal and acceptable. I have strong doubts about this practice. I phoned Damark on numerous occasions to dispute this charge,( a membership charge that I never ordered, nor wanted) and was treated very rudely by customer assistants and supervisors. I would like my $73.99 back, and will never shop from Damark again, nor recommend this company to any one looking for a reputable, honest company with courteous employees. Also, the merchandise as stated before, was very shoddy.