I went to the grocery to buy and the bill was 9$ I paid with my credit card and he told me I need 10 $ to pay so I told him he should charge me 10$ is it a problem of ribbis I general is every purchase made with credit card a loan because the payment is processed at a later time?
If you would have had a debt of 9$ to the store there would be a problem to pay back the debt with 10$. However here as you made your original purchase he refused to sell anything with credit card without a minimum 10$ purchase, hence you agreed to the higher price for your purchase. This would not constitute ribbis. Credit card purchases incur debt to the credit card company and are considered a loan from them, not from the merchant.