How do I make a complain about Powerbuy? The company is not answering. All they told me to do is wait and wait. It's almost a month already.

I Bought a Washer a month ago. And the bottom plate was missing. Their policy says if a product is missing a part, it can be returned. But many customer service staff were just trying to deny the existence of the bottom plate although the instruction manual of that specific model says the bottom plate exists. After many days of calling, more than ten times of calling, and wait over 10-20 minutes over the phone everytime. They finally said we would get a refund. We were told we would get a refund in 2-5 business days. But it's almost a month passed, we still don't get a refund. Everytime we call, they just tell us to wait. Everytime they say they would call back, but they never did. I don't think they take any responsibility as a big company.