Speak to the sub divisional engineer at your exchange. It's not an issue that they are trained for in their 'standard' training though, so it's likely he/she will not know what you are talking about. But if he's a nice guy/gal and you can get through to him/her, you might get it done.
The change they need to do is in the switching room, they need to pull out the wire end coming from your house and plug it into a different 'port', one that's serviced by a different route. They typically have a printed/chalkboard table on a wall listing which routes service what range of their end point 'ports'.
