DSL Vertrag Kündigung / Contract termination

I have already submitted the Kündigungsvormerkung on April. 31. I was told I will receive confirmation by mail but I dont received any yet. Also as I see i get charged for the next month and also get the following email 

Dear Rendak,

now the time has come, your DSL connection is switched on 5/15/2017, your order is now in Step 5: Installation of your connection. Please note this is the evidence of https://o2.de/goto/installierung , you'll find all information about a successful start with CO2 DSL and can immediately start surfing and phone calls on the day of the circuit.

regards

Your O2 Team 

Since I am left Germany I would like to know how long would it take to get the confirmation as well as instruction of what else to do following that.

 

I have read numerous posts of people not getting their confirmation and still being charged although clearly went through the official cancelling process, so I want to make sure this does not happen.

 

thanks