Hello! 

Sorry my German is not good, so i'll continue in English.

Please advise what to do in the following situation:

I had a landline contract, which i cancelled because moved out of Germany (used deregistration letter from BürgerBüro) . Received an email with cancellation. 

But till now (already 2nd month) they are sending me invoices to pay. 

I assumed that contract will be terminated in 6 days or so as desribed here Termination when moving abroad | Telecom help

but looks like it's not the case.

What should i do to properly terminate the contract and ideally received paid money back? 

Thank you for your help in advance.