The Cow - 2:275
"Those who eat usurious money rise up like one who is struck by the devil. This is because they say, "Usury is like shopping". But Allah has made shopping lawful and usury unlawful. And whoever receives a reminder from his Lord and desists, he may keep what he has earned in the past, and his affair is up to Allah. As for those who continue, they are the inhabitants of Hell, and they will abide therein forever."
They will remain in Hell forever:
Prophet Hud/11:106
The unfortunate are in the Fire. They will groan therein.
Prophet Hud/11:107
They will abide therein as long as the heavens and the earth endure, except if your Lord wills. Your Lord is the Doer of whatever He wills
Prophet Abraham/14:17
He will try to swallow it, but he will not be able to choke it down. Death will come to him from all sides, but he will not die. And a severe torment will follow.
Originator/35:36
For those who disbelieve is the Fire of Hell. They will not be allowed to die, nor will the punishment of Hell be lightened for them. This is how We punish the ungrateful.
The Ornaments of Gold/43:77
"They call out, "O Malik, let your Lord finish us". He says: "You will remain like this"."