I've looked at their ovo drive tariff and it doesn't say anything about 5p per kwh for charging your car, so it looks like they ended that. The rates are day 43.83/nignt 30.09.
Their FAQ under the question how much will it cost to charge my ev states:
"This depends on the size of the
EV’s battery. For example, a Renault ZOE has a 52kWh battery, so charging it with an average OVO Drive rate of 39.3/kWh would cost just over £20.44. The ZOE has a 245 mile range, which means you’d be paying £0.08 per mile. Interested in finding out more about charging costs? Read our guide on how much it will cost to
charge an electric car at home, workplace and abroad"