No replies from billing or correction of incorrect services being billed

I tried to upgrade my fibre to 1000/1000 which was available on the site.. After numerous phone calls and promises, i finally got hold of someone that understood the real issue. I was on a different backbone provider, so was told I would have to totally re-order on the new provider to get that service. I then was advised to cancel the 1000/1000 order which I did.

Month later, I got billed for pro-rata 1000/1000 (while still on a network which cant serve that), and full service for next month.

I then got hold of support on twitter and it was confirmed that I need to email *** for a fix. I've sent 2 emails, zero replies, and a bunch of excuses from twitter support.

I then found out on twitter that billing is non-existant, and they don't actually do anything. Not sure how to move forward.