Discontinued auto pay still went through

I cancelled auto pay via internet because I knew I did not have enough money in bank.  I did this on the 27th and my autopay was set for the 29th, which I know is short amount of time, but when I did the cancelation there was no indication that it would take any length of time, therefore, I assumed it was immediate.  I got notice on the 30th that the money was taken from my account and now had a negative balance and a surcharge of $35.00.

I called to get the money put back in, explaining the situation.  I feel money should not have come out. I have a confirmation number and screen shot the autopay was canceled. I also have screen shot of banking showing the $35.00 charge that I told them I could send as proof.  Ive been customer for appr 6 months, I pay on time.  They stated it was still in process on their end and could not cancel til today.

When I called today and spoke to Robin in customer service finanancial.   She indicated I canceled autopay to close to date of automated withdrawal and that the money would not get to my bank for 5 days.  If there was going to be a long time for auto pay cancelation to process, why isnt there any notification when cancelling this service??  In this day and age, most things are pretty quick and otherwise it is noted if not.  Because of this I have so far accumulated $35.00 in charges and was told by Robin that I had till the 15th to pay bill or I would be shut off.  I felt she was rude and treating me like I had a history of not paying, etc.

If I do happen to have a hard time paying, is there anyway to avoid getting shut off?