Ohme are known for Server issues & Sim (especially multinetwork sims) not selecting the strongest network, which makes you wonder why they switched Vodafone off, if you have a strong signal in your area. Why Ohme, didn’t think of putting at least another connectivity option on the charger like other manufacturers do bewiders me.
24hrs seems along time to leave it off, when a couple of hours should do, but if you continue to have problems tomorrow, get on the phone to Motabilty and tell them you have been having issues and you want an engineer out, as you spent yesterday on the phone without luck. The more people do this, the better chance of getting a better charger on the scheme or at least another option.