What should my friend do who reserved an Islamic website with a random Visa card, and cannot cancel the reservation or get a refund; should he utilize the website or abandon it?

Your friend must repent and regret what he has done, and resolve not to return to it. He must also strive to identify the owner of the credit card whose account was used to book the website, by contacting the service provider company. The withdrawn amount is considered a debt upon him. If he is unable to reach the credit card owner after exerting effort, then he should spend the amount on charitable causes, and the reward for this expenditure will be for the credit card owner if he is a Muslim. As for the website, he may manage it, and he must present material therein that benefits Muslims, encourages them to adhere to their religion, and informs them about matters of their faith.