No service from Chinese online retailer Banggood

One of the items I ordered from Banggood three months ago did not work. It was a scanner and has a faulty driver I think. It crashes on my fairly new Lenovo Carbon laptop (Windows 10). Banggood simply give standard formulaic responses to complaints and the manufacturer of the scanner (also a Chinese company) initially responded but never resolved the issue and then became completely silent. That was after I sent them a crash dump to show it was a real issue. Red (!) flag: It appears almost impossible to delete one's account. It cannot be done on the website and their blog gives an email address to use, but that does not exist.