Kwong Sang tea company

Have they gone out of business? I’ve been trying to purchase some of their tea tins to no avail. I was told by Roland Food that they are no longer stocking it. And Pearl River told me that they are “…sorry to say that we are not sure what happened to this company. Right now none of the american distributors have these teas in a tin anymore so that is why we have been unable to carry them.”
Does anyone know where I can still buy some?
Does anyone have their contact details?
I think they were founded in the 1930s so I can’t understand how they could just disappear overnight?
Thank you.