I'm sorry to hear you're having trouble making a purchase with Patreon. This type of service usually creates an automatic payment. You can update your preferred card through that link. It sounds like the preferred payment method could be expired, which is why you're having trouble making the purchase. If you have any other questions, you can reach customer support by clicking 'Contact' at the bottom of any PayPal page. Support is also available if you send a DM to @AskPayPal on Twitter or a PM to facebook.com/PayPal.
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