After several communications, they sent me a brand new unit
My experience with BT-Miners has been frustrating. At the time of purchase, I was told that I would only need to pay a minimal customs fee. However, this turned out to be inaccurate. The shipment was held at customs and I was asked to provide additional documentation such as the invoice and proof of payment. After several communications, they sent me a brand new unit. Thanks BT-miners for your support.