This is common for your bank to block a charge due to the dollar amount of the transaction. If your financial blocked the transaction from posting, you'll want to contact them to confirm your identity and let them know that the transaction is not fraudulent. Once your financial has been informed that you are trying to make a purchase for $350 with ToBeMagnetic.com, you should be able to try again and this time the booking should go through! To be safe, you can also check your bank account history to be sure the first attempt did not go through, as well as check your email for the confirmation of booking. Of course if you do accidentally double book, simply reach out to us ASAP and let us know.