Terrible customer service still need assistance.

I have been paying my bill every month for years. I do not check my Xfinity billing statements I just transfer the money into my bank account that I use to pay the Xfinity bill. Sometime last year in July I guess I paid my bill late by a day or two which doesn't make sense because I usually pay on the same day every month but whatever. Anyways I was charged a 10$ one time fee for not paying my bill on time (even though I still payed the full amount just not on the correct day supposedly) but the problem is I was never notified that I payed my bill late, they never sent me an email notifying me which is the only way I would have known that my bill was late because I do not sign into my Xfinity account ever, nor do I check my billing statements. Obviously a 10$ late penalty isn't a big deal at all, THE PROBLEM is this 10$ late charge turned into a 250$ charge because it compounded over the months. If I was notified the first month that I owed an extra 10$ because I didn't pay on the right day I would've instantly payed it. But I was completely unaware of this until they turned off my internet. What really set me off was when I called customer support and I was faced with someone who spoke with a heavy accent and could not have been more rude. I believe that the billing department is trained to be sharks because I have called Xfinity before for technical support and got great customer service, but the person I was just recently speaking with makes me never want to be apart of Xfinity again. I would still like to pursue this issue because at the end of the day I don't want to have to switch Internet providers I like the service not the customer support, but I am scared to call Xfinity back and get another rude person, and I cant seem to find Xfinities customer support email line please help and comment if you have had similar issues.