The only way how to change the credit card in the subscription is to cancel the current subscription and purchase the new subscription with the new credit card.
How to cancel subscription in Tabidoo
The canceled subscription will stay active until the end of the subscription period.
How to find the date when the subscription expires
You are free to buy the same subscription again for the same price, even if a new price list is in force. That means that if you cancel subscription of a plan, which is not in the price list anymore, you are still able to buy it again with the new credit card.
How to buy the plan again in Tabidoo