Early Termination Fee dispute

Hello,

I have had a comcast business account for several years and when we had changed our internet speed back in August, we had also come to the conclusion from the bill that we might want to look at different services because our business was moving to another space and the building we were in already had a service with a competitor, so we had no choice but to look into cancelling the service with Comcast. However, when we looked into cancelling, it was brought to our attention that we needed to fullfil 75% left of our agreement as an early termination fee. However, we looked into our last service agreement and we only had 2 months left of the current agreement so we agreed. But the termination notice said we owed $2,600 which was shocking to us as we had not renewed our service with Comcast. BUT upon further investigation, we found that when we went to downgrade our internet speed, they had renewed our service instead of a service request/action. Which was NOT what we had requested. So now we are expected to pay this $2,600 when we did not agree to any renewal of service?? As of right now, we are disputing paying anymore of the bills until we can come to an agreement on what we truly owe to leave Comcast Business. Can we get some help here on how we can dispute this termination fee??