Complaint about Gas.

Hi, my name is Athie Makara, I bought a 9KG gas at Caltex Theunissen, Free State last Saturday around 18:30 pm. Right now as we speak the gas has run out, this is impossible. Normally when I buy a 9KG gas it will take me around 3 months at least because I am not cooking with it, not a week. I went to the garage and the manager told me he 1stly have to test the bottle it was faulty or not but that is actually none of my business. This gas I ONLY used it for a heater, a heater that we dont always switch on, we onelyswitch it on when we bath in the morning and later when we come from form, we don't use it for any other things. Its HIGHLY impossible for that guess to take a week.