The short version, I contacted them back in June to notify them that I was going to upgrade to a 3 phase supply. Got a quick response that told me that the process was I needed to pay to get my current single phase smart meter upgraded to a new one and that I needed to co-ordinate the upgrade with the DNO work to remain connected. All made perfect sense.
I got a date from DNO on the 3 phase upgrade in September, and then went back to EON to get the upgrade booked in. EON took a payment of £159 for the meter upgrade and promised to come back to confirm the appointment. I then heard nothing, despite lots of chasing. The net result was an emergency appointment was needed with EON to get a new meter installed to remain connected to the grid, but sadly a dumb 3 phase meter was installed.
I now have in-situ a single phase smart meter that DNO have disconnected, so it's dead. My current gas smart meter is happily trying to talk to that (but obviously now effectively dead as well) and a dumb 3 phase electric meter.
No problem, I thought, I've followed EON's process, paid for a meter upgrade so I'll just contact them and get that booked in. This has proven absolutely impossible, I've emailed the people who took payment from me, contacted the team on WhatsApp, etc. I've now kicked off a complaint so that I can follow the formal escalation process but ultimately I've done exactly what EON advised me to do, paid for a meter and can't get one.
Any advice?