Fix Claude.ai Subscription Payment

My Claude.ai Max renewal refuses to go through: the site stalls at the “processing” step every time I try to pay with my verified credit-debit card, even though the card works elsewhere and both the number and available balance check out... (Budget: £10 - £200 GBP, Jobs: Graphic Design, HTML, Payment Gateway Integration, PCI Compliance, PHP, Technical Support, Troubleshooting, Website Design)