Damaged driveway

On Tuesday at about 5:30 we arrived home only to find our driveway damaged Telkom workers burrowed a huge hole and then covered it with a slab and sand. Our neighbours confirmed that a few Telkom guys just pitched up on our property and dug a huge hole left and to note we never gave anyone permission to dig a hole and damage our property. I do not understand what kind of people would do things like this and have no remorse. I want our driveway repaired and I am not going to leave this like this someone has to take responsibility. Firstly this is a danger as the hole is just closed with a slab and total disregard to other peoples property