Welcome to the o2 Community forum
If you would like to check with o2 customer services this may help you
you’ll need someone to access your account which can’t be done from here. If you message O2 on Facebook (https://o2uk.co/O2CFB) , Twitter (https://o2uk.co/O2CTW) or Instagram (https://o2uk.co/O2CIG) , they should be able to help you with this
It's in your MyO2.
It will tell you when your device payment ends or just your tariff if on sim only