I am on an annual subscription to dropbox. My payment was set up to automatically paid upon renew with my credit card. Since my last renewal my credit card was updated with a new expiration date. Dropbox declined my payment. While I tried countless times, I was unable to update my credit card information on their website. I had at least five chat sessions with sales (the only drobbox personel you can have live communication with) and they were totally unable and unequipped to provide any support. Technical support is only done through online requests. I deleted cookies and cleared my cache as suggested in the community help center with no success. I logged in using "incognito" on the Chrome browser as recommended, with no success. I submitted a formal tech support request and got a ticket#. I am waiting for a reply. It has only been a day. It is totally impossible to talk with anyone in technical support (no phone numbers except for sales) or to use the chat line to speak with a technician. There is no way to get in touch with anyone at drobox who can accept a payment if you are unable to update your payment information online. Like a monkey with a typewriter, I finally changed my payment option from Visa to Paypal. The transaction was processed immediately. Ironically, my Paypal account is linked to the same Visa credit card I was so frustratingly trying to use to make the payment.
If you are having the same problem let dropbox know. Maybe they will make it easier to communicate with tech support when there is a problem.