June here from Shopify. Thanks for your question!
May I ask what payment gateway(s) you are currently using for your store? You can confirm in your admin by visiting Settings > Payments now.
Also, by "bank card" are you referring specifically to debit cards, or all credit card payments as well?
Since each payment gateway has its own list of supported methods of payment, I'll have a better idea of what options should be available for your customers with a little more information about your chosen gateway.
If by chance you are using Shopify Payments, you can find more details about accepting payment by debit card here.
For other third party gateways, you can visit Settings > Payments > Third party payment providers for a full list of accepted payment types:
Let me know what you find and I'll be happy to continue assisting you with this one.