You have my sympathy, that’s why I’ll never have a smart meter – if I were a standard/E7 customer I have no problem with smart meters, but as an E10 user your experience is exactly what I fear.
EDF offer E10 – the night rate is pretty good, the peak rate extortionate – but no exit fee – you could try getting them to put a you dumb E10 meter in then switching as soon as you feel it polite, like the next day.
For info, Symbio and Yorkshire energy will both supply E10 meters at E7 rates and are currently cheaper than Economy 7 – I’m just in the process of moving to Symbio.
Best of luck
PS Symbio’s flat rate is good too – 11.99p +15.00 ppd here in the East Midlands region