How to make complain of low quality product? (Kuala Lumpur)

I have bought a spoil milk bottle from Goodday branch, in fact i bought it because they put so many award and certificate on it cover. When i write an email to them, they said will investigate and get back to me, and will replace me with new bottle. I found it funny, i dont waste my time to write a long email to them and ask for 1 milk bottle cost 7,5 rm.

However, that is not end of story, they never return to me. And after 3 weeks, i feel totally been cheated. I have write to consumer protection, or something like that but also no reply.

Im not sure if this thing happens too often in Malaysia and they just said that is "boleh", ???

Anyone have make a complain about a product and how did you do that? Happy to hear your sharing.