Android system developer

We are an internet service provider company that sells IPTV service on android boxes, and the boxes are free for the customers as long as they pay for the service, any time the customer stops using the service and subscribe to another ISP company the box should stop working, so I need an android system developer who can write the code that blocks the box on the box system firmware (we already have customized firmware on our boxes) so the code should be compatible and applied there.