Bad after sales service and poor quality

I had serious ankle fusion surgery in March this year, and as a pick me up after 3 months of no weight bearing, my daughter treated me to a beautiful pair of Holsters. Alas, after only 5 months, the strap just broke clean off. I didn't have a receipt, but the packaging was still intact and as good as new. Am I unreasonable to expect a pair of shoes of nearly R1000 to only last 5 months? Apparently, they can't even be repaired.