Package did not arrive

Waybill number : D3WPW6

A package was booked on over night on Wednesday 16 April 2025, it was collected Thursday 17 April 2025. It is now 23 April 2025 (7 days later) and this package is still in transit. I'm beyond ****ed off because I paid extra to have this sent over night and I'm being taken for a fool. When phoning courier guy they said courier guy changed the service to economy, I'm not sure who or what gives them the right to do so as a certain service was paid for. So my question is how is courier guy going to correct this matter