Reduced upload speeds after upgrading to 2Gbs download plan

My annual plan was set to increase so I opted to go to the 2Gbs download plan from my 1100/300 plan. I was assured by the CSR my 300 Mbs upload speeds would not be reduced. After the modem reboot, my speeds were reduced to 250Mbs. I went to the Xfinity office last night and they were not able to help. How can I get in contact with the right people to help? I got nowhere with the chat bots.