DFA refuses to upgrade upstream link

I have my 50/50 fibre line through Blitz fibre and cellc in Lorraine PE and according to Blitz DFA provides the upstream link. DFA refuses to upgrade their link from 1GB to 10GB and due to this their is a lack of bandwidth which is most obvious during peak times or over weekends when everyone is using their fibre line. I am paying a premium for this line ,but receiving second rate service from DFA who refuses to upgrade their link. Sort this out as soon as possible please!