Small change ******s

I went to buy shoes and I had a voucher of R419.30 when I purchased the shoes, I heard the gentleman saying the lady must put in R419 for the voucher. I told him the voucher is R419.30, he said oh the 30cents doesnt count. I said oh really i thought its only 5c or 10c. I then just finished up and left. but i had to pay in 30c on that voucher now they refuse to give me the 30c in my purchase. daylight *******.