why am i still not buying a new pencil case yet?

My friend salute me on my patient.Why i say so?This is because my pencil case zip already spoil and i still not buying the new one.Whenever i finish using my pen,pencil,eraser and so on,i close my pencil case on doing sieving the pencil case zip with hand.I'm lazy to go shopping to get the new one.I go to the same bookstore and look for the same size pencil case,but couldn't found anymore.And i don't care about that so much and leave it aside because still can use only the zip problem.