Selling goods to someone who pays with a credit card and giving a commission to the bank which is added to the price of the goods
Question

I work as an accountant in a company that has fairs. The customers pay through visa and master card machines in these fairs. The bank takes a commission from us on each selling process about 2 to 3%. We consider it as bank charges and add it to the price of the goods the customer buys.
The question:
Is it islamically permissible to use these machines? If it is not permissible to use them, then is who uses it making Riba easy? What we write as bank charges, are they actually writing Riba?.
Praise be to Allah.Firstly: 
There is nothing wrong with issuing and using credit cards, so long as that is free of shar’i reservations, such as charging interest in the event of late payment, or taking a percentage of the cash withdrawn, because this comes under the heading of riba, which is haram.  
Some Islamic banks have issued credit cards that are free of these reservations. 
Secondly: 
There is nothing wrong with the seller being paid for the goods with a credit card, whether the card is acceptable according to sharee’ah or it is not acceptable. As for the card that is free of shar’i reservations, the situation is clear. As for the card that is not acceptable, the sin of doing haram things is borne by the bank and the customer, and the seller has nothing to do with that, because he can sell to someone who has taken a riba-based loan, and the sin of riba is borne by the one who engages in it. 
Thirdly: 
It is permissible for the seller to pay commission to the bank, so long as he does not charge it to the purchaser, rather he sells the product to him as he would sell it to the one who buys it for cash. 
A statement of the Islamic Fiqh Council about credit cards says:  It is permissible for the issuing bank to take commission from the company that accepts this card and sells on that basis, provided that the company sells the product by credit card for the same amount as it sells if for cash. End quote. See the text of the report in full in the answer to question no. 97530. 
To sum up: It is permissible for you to get the price of goods sold by means of credit cards of all types, and it is permissible to pay a commission to the bank to facilitate this transaction, so long as the commission is not charged to the purchaser. 
And Allah knows best.