Fix Claude AI Subscription Payment -

My Claude AI Max plan renewal keeps failing at the payment-processing step whenever I try to pay by credit card. The card is valid and works elsewhere, yet the transaction is instantly declined before checkout finishes, so the subscription never activates... (Budget: €8 - €150 EUR, Jobs: AI (Artificial Intelligence) HW/SW, Claude (Anthropic), Claude Code, eCommerce, Payment Processing, SaaS, Stripe, Technical Support, Website Design)