Order cancellation

Dear team,
I have ordered a service on the 9th of Jun. Since than O2 hardly contacted me. Called 2 times but as soon as I picked up the caller hang up the phone. I was asked to provide information about the previous tenants contract to move forward. I am absolutely not aware of these information. Since this issue has been pending for almost a month I would like to cancel my order. It is not worth to wait for a service for months. Please help me assist how to cancel my order.
Thank you

Edit by o2_Steffen: Beitrag verschoben