Gyp
• Bamboozle
• Cheat
• Cheat (out of)
• Chisel
• Con
• Defraud
• Fleece
• Hoodwink
• Put one over on
• Rip off
• Rook
• Screw one's customers
• Stiff at a store
• Sting
• Swindle
• Take in
• Take to the cleaners