if the wiring at the back is to do with that extension which no longer works then you may get charged and will depend o engineer. mods will help but after you complete the email using contact us link then it will take 3/5 working days for mods to get back in contact with you due to number of other customers waiting for mod help
Those wires just look like spare external pairs. Its quite normal to see them tucked at the back of the NTE.
I believe I've sent ya an E-mail! Thanks for helping me out here, let's hope we can get it sorted and I'll be outta your claws for a while! Also on a sidenote, weirdly enough my homehub started disconnecting all over the shot while I was writing the e-mail, almost as if it didnt want me to get in touch with you!