Each request carries one message, and you may pay to send further requests to the same recipient. You are paying for submission, not for arrival. If that recipient has blocked you, every later request is held rather than delivered and they receive no notification of it. If they choose to unblock you, the held messages are released to them gradually, one at a time. If they never unblock you, the messages are never shown, and the payments are not refunded on that basis. Sending repeated requests to pressure, harass or intimidate someone, or using several numbers to get around a block, is a breach of these terms and will end your access to Kildr.