A while ago I bought a paper

A: This type of dealing is not permissible, rather it is Munkar (that which is unacceptable or disapproved of by Islamic law and Muslims of sound intellect) and a major sin, because it includes Riba Al-Fadl (usury of excess, selling an item for another of the same type, on the spot, but in excess) and Riba Al-Nasi'ah (usury of delay, conditional excess for delay of payment). (Part No. 15; Page No. 216) Both of these are Haram (prohibited) as is agreed by Ijma‘ (consensus of the Muslim scholars), because it can be a means of playing with peoples’ money and consuming it unjustly. In this sense, it has the same ruling as gambling, which is made Haram through Nas (Islamic text from the Qur’an or the Sunnah) and Ijma‘. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.