Die Rufnummernsperre ist aktiviert

Hello, my Alice O2 Landline is blocked since months "die rufnummernsprerre ist aktiviert" although I haven't requested it, and -i am still using and paying Alice internet.  I cannot call any number and no one can reach me, I was never informed, no email, no letter. ??! There is no customer service number etc, plus I can only use my handy to call the customer service so if it is the only way, I hope these won't be expensive calls.

my box: Alice WLAN 1421