Not replacing product

I bought Tupperware from one of the representatives . I had the bottle for a week ,which than it fell out of hand and it broke. The guarantee states that it does not break , stain etc but mine got a crack. I mean its plastic how does plastic break . The bottle was never frozen it was plain tap water inside the bottle. I have been waiting for over 3 months for an answer or feedback from my representative Keleabetswe Molipa ( Lesego) she cant answer me she has been ducking and diving me. What can i do because i feel is so unfair.