Why do you keep saying controllers can provide this upgraded service with the same staffing and equipment as E ?
No wonder you are exploited.
I suggest you talk to a US or Canadian ATC and ask them if they would be happy to convert their E above D to C without extra manpower and radar.
They would say they are not that foolish!
So why are you- or is it just resistance to change?
We're not the ones pushing for the change without adequate resourcing. Direct your questions elsewhere.
As I keep repeating & repeating & repeating. And you keep failing & failing & failing to listen: anything can be done with the appropriate resources. Give us the resources. Appropriate surveillance, appropriate sectors, appropriate staffing, appropriate equipment. Unfortunately our Dear Leader is on a mission from God (or is it Mammon) & won't listen.