Connectivity Issues and Cold weather?

I have been having connectivity issues since the cold weather started. So, I thought maybe there's a issue with the line out to the pole behind our location and called to see if someone could come out to check to make sure there's not an issue with the Comcast line itself. I just spoke with a Customer Service representative, my ref number is CR411025311. He told me that because i have my own modem, that I need to have My IT person test the hardware first before he even discussed a connection issue. Well, suffice to say, it's not the modem. It's been reset, tested, and deemed to be in perfect working order. I'm now being told that I will be charged to have someone come out to look at the line in the event that they don't find anything, including anything that is inside my business. I am not sure as a Business customer I feel very supported here trying to manage my business, and now, the having to pay a Comcast Technician to come out, all the while not being able to use my service because my connectivity is totally unreliable. I'm at a loss here. I have never been told that because it's not a Comcast Modem they can't diagnose connection issues, nor have I ever been told I'd have to pay to have someone come out to look at the line when a issue arises. After looking over the contract I signed I also see no mention of these new practices. Please let me know how to proceed.