There are two methods to remove credit card in Aliexpress. Alipay website and application.
1. Application
– go to Account and click on Alipay logo
– Remove the card from there
2. Alipay
– go to alipay website and remove the card https://intl.alipay.com/user/queryUserBindCard.htm
One of these methods should work for you. Otherwise contact with Aliexpress support!
Cheers