I'm sorry to learn about your experience with adding a billing method to your Upwork account. I can see that you have tried adding a credit card, and your Paypal account as your billing method. Upon checking, it looks like your bank has declined the verification charges on your card. I would recommend that you contact your bank directly and request for more information why your credit card was declined on Upwork.
As for your Paypal account, you may need to add an alternative payment method to your PayPal wallet in order to add your PayPal account as a payment method on Upwork.