Not upholding a reasonable warranty claim

As distributers and ambassadors of Assos cycling clothing in South Africa this company falls short on customer service. After buying a premium set of cycling shorts and using them for 3 months or 26 rides in total the material has worn through. Assos claims to be quality and will last for a long time, not so. My point of reference is that I have 3 other sets of bib shorts which I have been using for about 7 to 8 years on the same saddle with no issues. I would like to have the shorts to be changed or refunded please.