Does not respond to any form of communication

Buffalo does not respond to any of my emails or whatsapp communications. I have tried several times chatting to an agent on whatsapp, but there is NEVER an agent to chat to. They refuse to respond to any of the multitude of emails I have sent them asking for assistance regarding their invoice charges and why their 'docs and surcharge value' keeps increasing even when the value of the goods purchased either remains the same or goes down in value. I want them to explain this charge to me so that I can understand what causes the increase and how to avoid it otherwise I will have to stop making those purchases because if that charge increases everytime I make a purchase, then eventually the cost will outweigh the benefit. Neither there support email address nor their sales email address responds to my email enquiries and submitting anything through their website is a waste of time as well.