All I want is an exchange on poor quality merchandise

On the 26th Jan I bought a pair is shoes from RAGE. I paid cash for it on my debit card. Anyways I wore them for the first time this week on to find that the one shoe is seperateing from sole and the shoe cracked. Anyways I have no slip as I didn't think to keep it as I didn't think there would be a problem with the shoe. Today I go to return it only to be declined because I have no slip. Reason for decline is no slip no exchange nothing. The staff cannot make any discretionay decision on faulty merchandise due to poor quality assurance on RAGE side. It's the process they have, they have no access to go back and check up on past transactions on their systems because RAGE blocks that from their managers instore. The name is ampt as it leaves customers in a rage. Please hello Peter help me here. I don't want my money back all I want it an exchange for something else I even presented my bank statement as proof of purchase. Very irritated as I'm sitting with a pair of shoes I can't wear.