Sales Rep Won't Respond After Signing Service Agreement

Hello!

About 5 months ago, we wanted to add two more TV boxes. We got assigned to a sales rep, who told us our documents on file needed to be updated, and had us complete service orders to update the accounts. In the emails and phone calls, he promised us our previous "Service Discounts" would continue after signing the service agreements (that we were told we had to sign to update the account with the new documentation they needed and didn't have on file previously), and all we needed to do was get on a call together and contact billing, to update our account and reflect the "Service Discounts". After signing the documents, he has been unreachable. We have sent numerous emails to him, tried calling him multiple times, and he will not respond. We've tried calling the main Comcast Business hotline, spent 10+ hours on the phone and talked to multiple people, who have told us you need to talk to the sales rep, and won't escalate it to someone who can help us get in contact with the rep. I was able to connect with another service rep, who told me he couldn't do anything, and would email our sales rep and the rep's supervisor, yet I still have not received any communication from either of them, and it's been 3+ weeks since that conversation occurred. This is getting very frustrating, as all of our service discounts have been removed, as they were promised in our email communications they would be continue after signing the agreement, and we have been charged $400+ extra for the last few months. We may have to look into other providers if this isn't resolved. 

Thank you!