Disgusted in Levi

I recently purchases a Levi jean from the Levi store in Centurion mall. I had the jean for approximately a week and found that it stretched a lot, which I did not like. I then attempted to return the jean and was told that due to the fact that I had worn it, it would have to be sent away for assessment and that I would have to wait approximately 4 weeks to hear whether it will be exchanged, which is ridiculous. I don't understand why the store manager could not make a call and exchange my jean, as she would have been able to see that it is in perfect condition. The manager did however confirm that the range from which I purchased my jean, does tend to stretch a lot, which I was obviously not told when I purchased it as I would have considered the fact. Now, due to the fact that your staff aren't adequately trained, I have a jean that looks terrible after a few hours of wearing it, and which if I have it assessed, means that I will have to wait +/- 4 weeks. The manager also confirmed that it would have to be assessed as I had worn the jean, which I obviously did because if I had not worn it, I would not have known that it stretched so much.