to Cable Forum
When you purchased the land, did you have a solicitor do any of the checks (searches) to ensure the land was free of encumbrances such as easements for services which might pass over or under the land. Did the Council tell you that the land was free of encumbrances. It's always a case of buyer beware, and it's not necesarily the council that will know where services are, often even the suppliers aren't that precise either.
If the service is allowed to be there, but the checks you should have made did not show it up you will have to lump it. If checks were made by a solicitor or the council and they concealed facts, or did not find somethign they should have, you will have a legal claim against them.
If the service should not be there, it may depend on how long it has in fact been there, without objection by the council, as the previous owner of the land, as to whether rights of passage have arisen due to lapse of time (adverse possession).
Only if the service should not be there, and has been there for only a few years, could you have a right to demand it's removal, or a fee for the passage over your land. Whilst the fee may not be substantial. I would expect it to be greater than a subsidy off your current bill, since you would effectively be preventing enclosure and private use of the parcel of land, and moreover, the fee would reflect that you couldn't even pave or plant over the area (other than perhaps grass) since the utility company would expect to have ready access in the event of a problem.