Early termination fee sent to the collection

Hello, about 3 months ago me and my fiance moved to a new apartment and wanted to move our service to there. When we called about it they had us starting a new service (for some reason) instead of moving our current service. And they said we should sign some documents without giving "zero" explanation. Apparently they made us sign a year long agreement.

Once we moved into the new apartment we realized since the unit was a new built unit there wasn't a coax cable installed so we couldn't use our service. We talked to Comcast about installing the coax cable (you can check my previous post as well as my previous conversation here in the forum) and it took them more than a month to install a coax cable.

After about month and a half when they finally installed the cable we wanted to go ahead and activate the Internet and started using it. We tried many times by ourselves as well as with the technical support but we were "not able to activate" the service for some reason. So for more than 2 months after we signed the year long agreement we haven't been able to use the service at all (you can check my data usage), not even activate it. 

Later we wanted to cancel the service since we are not able to use it. Once we cancelled it they sent a bill for Early Termination fee of $100. When I called them about it and said that I didn't want to pay because in the agreement it states that the fee only applies 30 after the activation of the service. Which activation also defined as connecting to the service and using it actively. They said they would remove the charges. However they didn't. Then message them through website this time and they again said they will dispute the charges, but they didn't. 

Now we just got a call about our charges being sent to the collection which is not fair I think. We were expecting them to dispute the charges as they told us so we didn't do any payments and now they sent it to the collection. Could you help me with this issue please?