Remove a card

Hello, could you help me? I already tried to search for tutorials and contacted Riot's support but they couldn't do it. When I wanted to buy Valorant points, I added a debit card and I press the option "save information for next time", but now that I want to put another card, it won't let me remove the information from the previous one and it rejects any other number of card, do you know how I can remove the old card and put a new one?