when pills clock run to 0, pill dont desapear sometimes, still in the inventory with no timmer, and if you active again, its seems that have many seconds (sometimes minutes) left!!! the problem is that you can buy another one from the mall
to unbug this, try to activate again and wait till the clock reach 00:00, then sometimes disapear and you can get a new one
if this not work, and pill stay on your invetory try to repeat the action untill they disapear!