It didn't take six days to start drilling BluePheasant, despite how it sounds. Tunnelling is more complex than it might sound. Due to many factors, as mentioned above collapses and landslides are all complication that ideally (given time) engineers can figures out how to avoid.
It was on the news last week (two days after he had fallen in). The report said they didn't know where he was exactly - something that needed to be known before they could start tunnelling.
Such an awful situation. There does seem little hope now. Desperately heartbreaking for the parents, and awful for those attempting the rescue the fear they'll have calculated incorrectly and that the rescue might cause his death.