Fallas Discount Stores  -  customer service so rude, they stole me!

I went to the store on november 25 to do an exchage of two mens pants, when i arrive the cashier told me to leave the bag with the pants there and she ask me for the receibe so i gave it to her, then i went to pick up stuff (pretty much by the way) and i totally forgot abaut the exchange so i just paid the merchandice and i went home. I went to fallas again on november 27 to get my exchange and they told me that they didnt know where tha bag was, they told me to come back next day to talk with a diferent cashier so i did it and the other cashier told me the same, so ask to talk with the manager and they told me that she was not there so that i had to come back the monday 30 ! ok i did it i went again! the manager make me wait her for an hour! and she said that they just lost the bag !and that she couldnt do anything for me ! they stole me! no money back! no merchandice !