Poor customer service

I have been billed for my xfinity internet that I had canceled a day before payment due and when I check the xfinity app to make sure I dont owe anything and it says $0.00 and then the next day I get billed for $31.79, saying it was for the days july 13th - August 2nd but I had canceled the internet before that payment. So I just got billed for non existent internet. A couple weeks before this I had an issue with my payment for my mobile phones but it was on your end that the bill wasn't being processed right because your employees couldn't update my new card right, and so my bill went from 130.32 to like 226.66 and I had called customer service because it was not my fault the payment was late and the 2 employees I talked to at the billing department told me that I would not have to pay the 96.34 and it would be waved after my payment of 130.32 was payed. I paid the 130.32 and a week or 2 later mine and my wife's phones were shut off because they never waved the 96.34 fee. I had called to dispute it, no one was willing to dispute it, and I had transferred to a supervisor and a manager and they wouldn't resolve the issue. So your company just likes taking money from customers for no reason?