Keep getting charged for canceled account.

Hi. I have been an Xfinity customer for 2 years and recently had to end my service before the contract was up, because I moved and got married. I had canceled my whole account in May, which the representative said was 2 months before my end date in August. After the first phone call I was under the impression everything was taken care of as they told me my account was canceled and I was good to go. A month later I got charged for the month of June. I called back again to cancel and they told me there was an early cancellation fee of 100 dollars I needed to pay, which the representative did not tell me about the first time. I payed this fee over the phone and they told me everything was officially canceled. I returned all the equipment that was in my house and thought I was done. Then I get back from my wedding and see I have 368.67 dollars worth of charges on my account for an 150 dollar cancelation fee and unreturned equipment. I called a representative to see what this was about as I already payed an early cancelation fee and returned my equipment. They assured me from their end they did not see any charge for equipment and they would take care of the early cancelation fee as I had already payed this after I spent almost 2 hours on the phone. I have just received a text I have been sent to a collection agency for my unpaid bill. I am so frustrated and tired of being on the phone for hours and paying more money thinking I have resolved the issue just to get a text the next month that I have unpaid charges. I tried signing into the collection agency site to see what I was charged for and it said it could not find my account. I don't know what to do.