Product: Debt collection

I was a customer of XXXX  for about 4 years, making my payments on XXXX XXXX, XXXX I changed address and had the internet service transferred to my new XXXX year I have to renew my XXXX  plan, I called a month earlier before the plan expires and they told me its too early because my plan wont expire until a month time, they wont be able to give me a plan, so I am to give them a call back two weeks before the plan expires, I did so, one agent told me that I would not get back the same plan. ( It was {$66.00} at the time ), I asked why is that, the agent said that plan is no longer available.I asked for an affordable plan and I was told that the best offer they have is {$95.00}, I said no way, from {$66.00} to {$95.00} that is too much just for internet, they told me to call back XXXX weeks before XXXX there will be promotion, I did call back that time and again there is no promotion and there wont be no promotion for the rest of the year but i can keep calling and check.I said I saw advertising on the television for internet for {$40.00}, their response was, that promotion is only for new customer, so the best they could offer me is $ XXXX was very difficult for me to pay that much because I was only getting part time hours and have other bills payment too. Before each bill cycle I would call trying to get my payment down without being successfull.I started falling behind with payments and I called and asked for a payment plan and I was offered one, two months into the payment I am seeing bills online for different amount ( higher than what the payment was ), I called XXXX and XXXX agent told me that ( each time you call is a different agent with different information ) that is what I am to pay each month ( {$110.00} ) and that I am getting the highest speed megabyte at a low price and the payment is as is. In XX/XX/XXXX my service was disconnected without me knowing. I was not getting any internet sevice and i called customer service and they told me that from their end everything was connected so they had me on the phone running test, having me resetting the modem and the internet was still down, so they set up an appointment for a technician to come out, I was lucky to get one the following morning.The technician came tried everything nothing worked, he even changed the internet box and it still did not work, he then called the office and they told him that my service is disconnected for {$110.00} and said no way Ive made that payment two days ago, when i checked my payment history, the payment did not go through, made a mistake and used a card i had on file that was cancelled.I said after being a valued customer, I did not received any disconnection notice and if the technician did not come any of the agents did not see that my service was disconnected.The fact that my service got disconnected I had to pay {$63.00} for an adt technician to come and reset my door bell camera. I was getting overwhelmed on high bills from XXXX, even tried talking to supervisors and I was told that they are not able to help reduced my monthly payment and if i dont pay it, it will go against my credit, so i asked them to disconnect my service and send me a label to return the equipments, I returned the equiptments in XX/XX/XXXX, owing {$110.00} and they billed me {$350.00}. In early XXXX I received a message from a debt collector Harris and Harris saying that they need payment they are acting on behalf of XXXX, every day at least XXXX times XXXX and XXXX called me back to back and sending me text messages twice per week that they need XXXX XXXX XXXX XXXX and XXXX XXXX sent collections to my credit report stating that i owed $ XXXX is very damaging because this has never happened before and the way how XXXX  dealt with the situtation was very bad and adding amount to my account that is not correct they should be held responsible for damaging my credit.