Locked Out by Poor Quality Lock

I purchased a small combination lock code P2K10U from a large national retails store, supplied by Fort Knox. The product is advertised on its website as "ideal for locking luggage, sports bags, and gym lockers" .... so I purchased the small lock for my gym locker eight days ago. Two days I noticed that it was becoming difficult to get the lock to open, even though the combination was correct. After trying for ten minutes, it opened. Today after I had showered at gym, I tried to open the lock, using the correct combination. The dials moved but the shackle would not budge. So there I was in all my naked glory, struggling to get my gym locker open. Three other guys tried to open it, including gym management. It was impossible. Let me confirm again, the combination was absolutely correct ... no question about it. Regrettably the Fort Knox lock is sadly inferior, a poor quality product that cannot be trusted. It looks good but unfortunately, we had to cut the shackle so that I could eventually get dressed. My next battle is to get back the R 140 I spent on it. I will regard the Fort Knox brand with suspicion, for future purchases.