Is it lawful to buy cash by credit card?

Question: Is it lawful to buy cash from the shopkeepers by credit card?

This is considered usury under the image of trading. In this process, the person who is in need of cash will buy from the shopkeeper, for example 97 liras in cash for 100 liras by credit card. Shopkeepers always have to get the commission fee of swiping machine (POS) from the buyer. The difference in this transaction (3 liras) would be considered as the interest for a “97 liras debt”.

Please see another answer alike :

http://www.islamandquran.org/fatwas/is-it-permissible-to-buy-gold-in-installments-by-using-credit-card.html