Its sorted out...
CPW do open their boxes & in the case of the
they install an additional navigation package called CPW Navigator.
The reason my phone would not register, is because my sim had not been enabled for the
service. I called T-Mobile UK out of sheer frustration. The guy said the problem was due to my sim not having been enabled for the service. He told me he would enable it & to give it 30mins. 20mins later I received an email. I then tried registering on instantemail.t-mobile.co.uk again & this time no problems with registering.
The frustrating thing is that none of the errors mentioned anything about my service not being enabled... Instead it lead us down a path of potentially used handsets!
Anyway, to all who have helped & advised me I would like to offer my gratitude. Thank you all... You guys rock!