UK Landlord Forum / Life

Hi,
There is a maintenance company for the building for my rented flat.
The owner from the below neighbour reported a leak to the maintenance company. After 3 weeks, the maintenance company sent my an email about the issue.
My tenant knew it and he didn't notified me.
What are the responsibilities of a maintenance company. Should them notify me earlier? Can I blame them responsible? How can I complain about them?
Thank you

Did the maintenance company first have to visit the below neighbour's flat to determine the source of the leak?

If so, that would take time to arrange and carry out.