Autopay

I’ve been on Xfinity auto pay for years , the take their payment every month on the 28-30 of every month ,they took the June payment on the 30th of June and now they say my payments late and they never received it, and said no I didn’t pay the June payment, I have all the proof that they took the payment on the 30th of June 

now how do I get them to credit my account for?