I switched the device on my phone to my xbox and it said i reached the maximum devices, now i cant watch anything as i cant register device, i dont wanna pay for a month and i cant use it...
Welcome to the forum. Sounds like you've reached your device limit. If you've watched on four different devices in the past then the device limit rules kick in, where you can now only add one new device a month, even if you delete several.
Have a word with Live Chat, explain what's happened and see if they can sort something out for you as a courtesy.
