Ruling on deducting from the price of goods when returning them

Question:
The questioner says: If a buyer purchases a garment for one hundred riyals, for example, and finds that the garment is not suitable in terms of size, he goes to the seller to return it, but the seller refuses because the seller had stipulated that sold goods are not to be returned or exchanged. When the buyer was unable to return the garment, he said to the seller: "Take the garment and give me fifty riyals instead of one hundred riyals," and the seller agreed. The question remains, O honorable Shaykh: Is this considered riba?

Answer:
There is no harm in this if he purchased a garment or something else with a definitive purchase that does not include an option, then he went to his home or elsewhere and then returned and said: "The garment did not suit us." The seller is not obligated to accept it; the sale is completed. The Prophet (peace and blessings be upon him) said: If the two sellers separate and they did not stipulate an option, the sale is binding. So if he purchased a garment, a vessel, a beast, or a car, then he left and departed the assembly, and then returned wanting to return it, no, he has no right to return it except with the seller's consent. If the seller says: "No, the sale is completed between us," then he has no right to anything unless he finds a defect in it. If he finds a defect in it, he has the option. So if he sells it to the seller for a lower price, there is no harm, no blame. He bought it for one hundred and sold it for fifty, or eighty, or seventy; there is no harm in that. Yes.

The presenter: May Allah reward you with good, O Shaykh.