A jump start is for a battery that will take a charge and turn the engine. If the battery is dead, swollen, or keeps going flat, you will be told. This is not a full electrical diagnosis and it is not sold as one.
Sea air and short hops around Southsea and Old Portsmouth are hard on batteries. So is a car left at Portsmouth International Port while the driver is away. Say how long it has sat.
If the vehicle still will not move after a start, recovery is the next step. The two jobs are priced separately.