Is the seller obliged to accept the return of a device whose defects were mentioned in the sales advertisement, while the buyer rejected that [information]?

The seller must detail the defects of the commodity at the time of sale; a general description is not sufficient, because concealing a defect is a forbidden deception. If the defect is clearly explained to the buyer, then he has no option to return the commodity unless the seller agrees to annul the sale, which is religiously recommended. The buyer's failure to read a written statement is not considered an excuse for him.