Generally, a contractor can't connect to power lines or install the meter. A contractor only puts in the stuff on the customer side of the meter. The service side of the meter is almost always done by the electric service provider.
It is also possible that the electric provider has some form of a blanket right to use aerial space in your city/county.
It generally costs several thousand dollars to install or move a pole.
Also, as already pointed out, a previous owner of the property must have signed an agreement to have the pole installed in the first place. If it has a transformer, that transformer is designed to supply more than one house so installing it for a single residence was probably pretty expensive.
Although you did not state the cost, I would guess that going underground would cost about $500 to $1,000 a foot.
P.S. Did they come onto your property? Did they damage the lawn with tire tracks? You might have an argument for trespassing and/or intrusion then.

