Using a credit card that is not covered (MasterCard) but in the following manner:
Firstly: there is no Islamic bank here (I live in Germany)
Secondly: the company that issues the credit card does not provide current accounts to cover the card or even any other bank accounts to cover it, but it is possible to put money on the card by transferring money to the bank company account. I only use the card for buying things so as to avoid interest. Before buying anything I put money on the card to cover the value of the purchases, and I do not use it for anything else so that there is no room for delaying payment, because any delay will lead to interest being charged. Is it permissible to use it in this way?
Is it permissible for me to tell my friends about this card even if they use covered credit cards, but they are with riba-based banks, and that is because this company does not charge annual fees for the card?.