3x21” Sanding belts 40 Grit

Two packs of 3x21 Sanding belts 40grit Ordered 3 x 18 Sanding Belts 40 Grit, Aluminum Oxide Sander Belts for Belt Sander, 12 Pack(3x18 Inch, 40 Grit) but the product sent was 3x21” and it won’t fit the sander. Noticed the wrong size too late to return them Originally paid $20.99 Selling both packs for only $10 Cash only please