E.ON Next use Kraken IT plaform by Octopus Tech. So it gets monthly billing.
E.ON own power gernators. It has trnasfered it domestic customers to E.ON Next where is assigns its renewable output. It sells it dirty energy for cheap to Utility Warehouse to push through it's MLM model
It has developed EV tariffs that have attracted many new customers.
Like many Energy companies, several Facebook groups have sprung up, where customer help each, but like many groups on FB beware of scammers or just that whose interests are not your own. While there can be good advice there can also be plenty of misinformation