No reinstatement of extension after master socket install

[#1]

My elderly parents had a problem with their broadband and a new 5c master socket has been installed.

The previous master socket had an upstairs extension hard wired into it. 

The engineer removed the 'knock outs' of the new box and fed the wire in, but did not connect it leaving them without a phone upstairs. 

Should this have been done to reinstate the equipment as he found it, or is this standard practice from openreach?

[#2]

or is this standard practice from openreach?

I'm afraid its standfard practice. Any internal wiring is not the responsibility of Openreach. If they were to rewire it , they could possibly be held responsible,

Its not difficult to rewire , you don't need any special punch-down tools like previously, there are locking connectors. If you are near your parents , its a simple job.

Assuming what's been fitted is a new NTE5c with a Mk4 faceplate, you simple unclip the faceplate and attach the extension wires to the faceplate see here https://www.run-it-direct.co.uk/blog/installing-a-mk4nte5c-combined-socket-14.php using the camlock connector. Then clip the faceplate back.