"We may retain your personal information for the longer of three (3) years after we become aware that you have ceased using our services or for so long as necessary to fulfill any contractual obligation governing the information or our legal and regulatory obligations. However, we may not know if you have stopped using our services."
Data is retained for at least 3 years after you stop using the service, and since the company acknowledges it may not know when you've stopped, retention could effectively be indefinite.