Bad quality

I purchased sandals in September. My wife wore the one twice and it broke. My mother didn't even wear hers and it was broken. I went to the Dunns store in Mitchell's Plain Promenade to get assistantance however they didn't want to assist me because I didn't have the slips even though it was purchased on my account they did not want to assist me with pulling up the transaction. How is it possible that you cannot provide assistance with these kinds of issues. The quality of the sandals is poor, the service I received was unacceptable as we as consumers have the right to quality products.