[/QUOTE]Agreed, But I was tricked into signing it after being given false information about the charges
That doesn't make the charge invalid. The merchant's cost to perform the service is irrelevant to you. Selling a service for more than it costs you to perform is how you make a profit in a service industry. It may be unethical to lie and say you are just passing this charge along to the customer, but that doesn't make it illegal.
You just said two posts ago that there was $60 on the receipt for unlocking.There is no mention of unlocking and registration in the receipt.
You can keep thinking that these things you believe will get you out of paying $528 matter but they don't. Go ahead and file a dispute with your credit card company and see what happens.