I have created an account with the  Zugangsnummer and Persönliches Kennwort numbers that was sent to me via mail.

I also entered Kundennummer in to my account. But when I click my contracts in customer center I see no contracts listed, I click + sign to add a contract and it lists my landline number with the same Kundennummer. But it mentioned something like " this account is under another contract holder" so I can't manage that account.

Another issue is: I can't change my address online but it apartment number was entered incorrectly. as 17 instead of 17B. how can I get this changed?

(I can't reach to call center because I can't speak German)