Autopay - debit or ACH security protections and gaurentees?

I would like to know what enhanced security T-Mobile has in place to protect debit and routing/bank account numbers for customers? 

T-Mobile has had data breaches in the past, now they are asking customers to trust them with your specific bank routing/account number (or debit) to continue to receive their autopay discount.

I’ve always used a credit card for autoplay because if there is a data breach and my credit card # is stolen it’s easy to call the credit card company to dispute the charges and the credit card company takes care of it. 

With a debit card number or direct access to your bank account (routing # and account #) you could lose all your money from your bank account by hackers if T-Mobile has a data breach before the breach is publicly disclosed. This means the customer will have to battle with the bank to recoup any funds if there were fraudulent debits - I can I see the issue now:  the bank will try to insist that the fradulant withdraw made by hackers with your routing/account details stolen from T-Mobile are a legitimate transaction; this has the potential to be a HUGE mess! Someone could end up with sizable fraudulent withdraws end potentially end up with a zero balance in their bank account.  Then you'd end up fighting with the bank to get your money back and all the while you are missing other payments because you've been cleaned out. Thus impacting your credit and all aspects your life.

So I ask, before I give my routing/banking/debit details, what protections and guarantees/assurances is T-Mobile provided to keep the data protected?