I've posted this before that you should never use a Debit Card for any transaction that you do not personally accept.
Debit cards are linked directly to your bank account. If they accidently overcharge, someone steals your record from their system, or any number of other scenario's you are screwed.
Yes, you do have rights as a Debit card holder, but once they money is gone, its gone and you can't get it back until the dispute or problem is settled. They can clear out your account and your out until its fixed. With a credit card at least its not your money and you have alot more rights and say so in whats going on.
I would never use a Debit card period, but if you do have one at least only use where you are personally making the charges.
Its just a bad practice and anyone who tells you "Its ok", well its not there money, its yours and I would do whatever I could to protect it.
EFT or Electronics Funds Transfer is different, because you can set the amount they are allowed to take, plus its traceable back to a specific company or person, where debit cannot be traced to an individual.