So for the last few days my internet has dropped substantially from 39mb download and 10mb upload to 18mb download and 0.4-5mb upload.
I have restarted the router by holding down the reset button etc but this has done nothing.
What can I do?
You need to call the broadband team. See link for number.https://help.nowtv.com/article/how-to-submit-a-broadband-complaint1
This link also shows any planned outages as well wide spread faults.https://help.nowtv.com/service-status