My girlfriend has the same problem. She wasn’t able to get through on the hotline and no answer on the email. She went into a ticket office here in Berlin and they told her they can’t do anything about the payment problems and to call the hotline. Total shit show.
The 9€ ticket was amazing and could be purchased without a subscription. Why are they forcing you to have a subscription for the Deutschland ticket?
There a bunch of different providers. Some of them allow other payment methods like credit card or PayPal and don't require a subscription like DB. I use the HanseCom Deutschlandticket App and it lets me pay monthly with PayPal.
The 9€ ticket was amazing and could be purchased without a subscription. Why are they forcing you to have a subscription for the Deutschland ticket?