Diabolic Experience

I dropped off 2XLarge paxi bags at PEP Cape Gate and I was told they don't accept them if they are additionally sealed with sellotape. If that's the case, why isn't it written on the bag / told when purchasing it? I was asked to buy 2 new bags as they wouldn't ship the ones I had. This is not fair on my part & certainly not happy. How on earth would I known that they don't take bags if you have chosen to seal them beyond just how the bag comes?