Standard of clotjing

I purchased a DH jean at Truworths vaalmall but its not even a year its shredding on the back pockets and on the front near the zip, I took it there and showed them how it is to my suprise I was told they cannot help me because they cannot find my sale on their system, so I was not helped, I bought that label because its expensive and it is meant to last for years... So my dear people next time before you pay for their clothes you should inspect them thoroughly whether they are in good condition or not