Xfinity fraudulently changed my account

Where to begin.

1. When I switched to Xfinity Mobile from Verizon, they told me they would pay off the remaining balance on my device which was $866 to Verizon. After 2 months, they sent me a $200 gift card to pay it off, leaving me with a balance of $666. I do not have the money to pay all at once. My Verizon bill is now in collections and is going on my credit report. 

2. Yesterday I submitted a question online and received a email later saying “thanks for reaching out to Xfinity, to continue with your request please click the link below.” So I did and it took me to a page that wouldn’t load and then said the link had expired. I assumed that email was a response to the question I submitted online. No. I then received a email saying “your service change request has been confirmed here are the new details to your account below” . They CHANGED MY INTERNET SERVICE from $55 a month for 5 years to $65 a month for 1 year, $75 a month after one year. When I called to ask how that happened without my consent, they told me it was because of the link I clicked in my email confirming changes I NEVER REQUESTED TO MAKE!! They then told me there was nothing they could do to lower my bill now because the changes have already been made. Xfinity is a scam and they do stuff without your consent. 
3. I called back again to cancel my service and the lady did lower my bill to $41 for a year which was nice but I am very upset I am not locked in at a low cost for 5 years anymore. When she made the changes, I had to actually CONSENT by checking agreement boxes. So if someone could explain to me HOW my account was changed in the first place without me checking any agreement boxes, that would be great. 

Moral of the story,

1. Xfinity owes me $666 that I have not received to pay off my Verizon device.

2. Xfinity committed fraud by changing my Internet plan without my consent. I checked ZERO box’s for that change to be made.