SIM Partner card

Can someone from O2 tell me when and where did I sign up for this “Partner” sim card? Not only I just had issues with2,5 months waiting for the DSL to finally start working (weird charges pending though), now I also realised that since a longer period of time you charge me for some additional card that I actually don’t need (family living outside of Germany) and whenever someone from O2 called, they never mentioned any costs for this card....Since my termination date is coming closer, I am really more and more confused about O2 and after 5 years thinking of the contract termination......