Good news!
My S7 edge came back from Samsung today.
I noted to them of the three issues I was experiencing:
1: AOD being dark grey not black
2: USB port not fast charging until cable reconnected multiple times
3: Battery not holding acceptable charge (phone is 14 months old)
Phone came back like a brand new device. Obviously they've transported the motherboard into a new unit, as everything else is new.
They did the turnaround in under 48 hours as well. this was at Anovo in Norwich.
Anovo's Google reviews rating stands at 2.9, no idea why, maybe they were poor at one point, but my experience is 5*
My A-Novo experience was slightly different. Ended up taking them to small claims court. They paid out £534 to me in the end.
Sent phone away initially for a screen repair. They said my SIM tray was stuck and wanted £90. I asked several times if that meant the screen would be repaired and they said yes... It didn't.
Received another bill for £200 for the screen. At this point I felt I had no choice but to pay them. Otherwise I'd have a phone that I had paid £90 to repair still with a broken screen. Argued about this for hours via escalations etc and they dropped the price to £200 all in.
Received phone back. Memory card not working and home button rocks in the recess.
Sent it off again. Memory card was fixed but home button still to this day rocks despite having sent the phone away to them 4 times and spent 6+ hours on the phone to them about it.
Only decent outcome is I have a cosmetically new phone albeit with a dodgy home button and £534.