Value Co. Disgusting

I bought double wall glass coffee cups and one of the cups when I washed it my finger went thru the glass inside the bottom of the cup. I took it back and the manager of the store was very rude and unfriendly. I tried to explain but she turned her back and walked away. She comes back and says we dont change glass but there was no sign saying that. She carried on saying no and gave me a dirty look and walked away again. Value at game city center (City View Shopping Center) at Greyville. I have written to the Heas Office and no reply. This store the staff are so unfriendly and the manager (Female) is so rude . I/We will NEVER ever go into a Value store again.