I have used their toner cartridge before with no problems. This time, however, l encountered an error message when l inserted my new cartridge in my printer. They offered to send me another cartridge upon receiving the defective cartridge at Their expense. I would have done this but l explained that l had an important job to get done and could not wait for a new cartridge to be mailed out. They offered to refund my money which they did. L am very pleased with how quickly they acted.