Praise be to Allah.
It is not permissible to use this card, because it is based on riba, which is a loan which brings a benefit to the lender.
That is because you are borrowing 20,000 dirhams, and paying it back to them with an extra amount of 700 dirhams every three months, which they call fees, which is not right. Every dirham that the card-issuing company takes in addition to the actual costs is riba, and undoubtedly the actual costs cannot under any circumstances reach this large amount every three months.
To sum up, it is a trick to engage in riba, and calling things by something other than their real names. You must beware of that and not get involved in this transaction.
Dr. Muhammad al-‘Usaymi (may Allaah preserve him) said concerning one of these dubious credit cards: If it is as the questioner described, it is haraam. I also know that the bank charges a fee every month to the customer under the name of fees, but undoubtedly the fees for credit cards that offer loans should be based on the actual costs to the issuer, which is the bank. And it is not permissible for it to make a profit from those fees, because the loan offered via the card will be a riba-based loan if what the bank charges as administrative fees is more than the actual costs. End quote from the shaykh’s website:
We ask Allaah to help and guide us and you.
And Allaah knows best.