Pathetic service

I am experiencing very slow speeds in the evening, technician arrived without contacting me and informed me he will have a look at the issue but to my surprise the call has been resolved without confirming with the client. Line is fine during the day but at night my 10mbps line turns into 2mbps..... The field I am in requires constant vpn access and I cannot connect with 2mbps. This issue has been going on for years(see all previous refs) and gets sorted only to have the same issue a few months later. I am currently paying for a service I am not getting. Please see new ref: ********** 0 and all previous refs on my account.