Verizon Wireless No notification that changing to credit card would eliminate autopay discount.

I am signed up for autopay and electronic statements with Verizon Wireless.  I changed my method of payment from my checking account to a credit card last month.  There was no warning that this would eliminate my autopay discount.  I never stopped the autopayment, only changed my method.  Today 4/5/19 I spoke with "Jesse" on Verizon's online chat feature.  She informs me that it is mentioned on the bill.  The bill I don't get in the mail that is a zillion pages long and now on my mobile phone.  I don't understand why there isn't a warning when changing your payment method to let you know at that time so that you can make an informed decision.

Because I have multiple lines it effected every line - she says I was charged $30.  They finally agreed to refund $15.  (Although my phone app has a feature that shows me what has changed and it says I was charged an additional $10/line.)  Another source of consumer confusion.

I believe Verizon should be forced to add clarification to their site so that others know a simple change of payment method can cause them to be charged additional fees.  Banks have to have everything spelled out, why don't they?