Contact & support
Last updated: 4 November 2026
Contact the operator
Operator: Changsha Baichen Enterprise Development Co., Ltd.. Brand: SUMERU Sutras. Email: services@buytcn.com. This inbox handles product questions, file-access problems, refund requests and privacy enquiries.
Help us locate your order
Include your order or receipt reference, the email used at checkout, the product title and a description of the issue. For file problems, tell us the device and PDF reader you used. Do not send passwords, full card numbers or identity documents.
Billing questions
For an existing purchase, check your receipt to identify the seller and payment service. If your receipt identifies Paddle, you can also contact Paddle buyer support at paddle.net. Paddle cannot refund payments made through a different provider.