not treating the customer fairly

I am so disappointed with the service i got from Refinery, I made a lay-bye and it is still active, I went to Refinery to advise i am going overseas and will not be able to fulfill my commitment because i do not have the original slip but have my identity card and because there is the duplicate slip as this is a lay-bye, they want to give me a voucher that is only valid for a year and ive told them that i will be back in two years. they have all corresponding information my identity card is proof enough. i want my cash back and they have not responded. its unfair