Sennheiser PRO

I ordered 2 soundbars from them, order number ***. I called customer service to return them to sender while they were shipping to me. They were able to have one of them returned to sender, and they gave me a refund after 2 weeks. Then they said if I want to return the other product, I have to get my own label. I did and shipped it to them with the tracking number ***. I have been calling them and telling them I returned the device and that it arrived to them on August 17. I have contacted them many times to let them know, and I still can't get any help. There is no chat or phone number to talk to anyone. No one answers emails or Twitter. I can't get my money back for something I returned, and it's been 20+ days since it was delivered to them.