UNREASONABLE RESPONSE FOR TORN BOOT

I bought a Boot on the 30th of April from Rage in Bayside Table View. I wore the boot once and shoe tore on the day. I went to the store to request a refund or an exchange for the same boot in a good condition. I was told that since the boot was on sale when I bought it, I can not be refunded. If I prefer taking the same boot I must add on to make up to the cost of the shoe. I am now stuck with a torn boot and no one from the store understands that I was simply returning the boot due to the poor quality which resulted in the boot being torn upon wearing them.