I'm with Talk Talk business and it turns out they give a Static IP address as standard.
Therefore I wasn't able to change the MAC address in the router settings, and getting a new router didn't work either.
I rang them and asked for a new IP address and they have done that with no problems at all. Now I have a completely different IP address that isn't even remotely like my old one :D
Have also asked for it to be made dynamic so I can change it for different accounts if I want to open more than one.  | 
