Epson is advertising false information

Epson has advertise a promotion of cash back when You bought a printer.I bought a printer from Fnb from Fnb connect I provided Epson with proof of invoice but every time they have different stories that the invoice is not correct.Epson is doing false adverti*****t as they do not want to pay back the promotion as advertise.This must be investigate by the adverti*****t busy and the ombudsmen for adverti*****t