After reinstating service Comcast keeps charging our small business for ETF.

I keep running into dead ends while trying to resolve why we keep getting billed for early termination fees (plus other fees) if we have internet service in our new location. In December 2016 our small business moved from a building office to our home and internet was transferred to our new location. Although in one point the service was canceled (without knowledge of ETFs) we inmediately requested the service to be reinstated (as they did) and moved service with us to the new location. However, we continued to be billed for early termination fees. It's now over $1200 in charges for ETF and God knows for what else yet we pay our new bill monthly. 

I contacted the billing department several times. I had been told by several service rep the ETF will be removed but the charges keep showing up in my bill. Once I dont pay the bill they cut services, and of course they keep charging our business for late fees, disconecting, connecting, etc. etc. I cannot keep doing this. My business needs internet up and running. I don't understand why they are not capable to erase ETF from my bill. Is very simple, there are no applicable ETF because I have internet service (well most of the time until they decided to cut it for no ETF)  under the same business name. 

PLEASE HELP. We are a small home based business and these excessive ongoing charges are killing us. Otherwise, I am going to requested cancelation (they probably will charge ETF again) and call another internet provider.