Guessing you're in Wales? Situation is different there to England, there is no legal requirement not to travel in/out of different tier areas in England so no police enforcement and no fines. TBH if you get in your car, drive to a shopping centre, go to the Apple Store wearing a mask & staying away from others as much as possible, collect your phone in 15min and then get in the car again and drive home (and do appropriate hand hygiene etc.) you're at less risk than if you went to a restaurant/pub for the evening.