My old (2006) T-Mo XTRA SIM was finally cancelled (I assume for lack of use, as I hadn't used it in over a year - it did have a €12 balance on it).
Is it possible to re-activate a cancelled / dormant XTRA sim? If that's not possible, I'll just get a new one on my next trip in January (my Kundennummer is still active on the website, hopefully I can just add the new sim to my existing account).