Underground wire replacement

Hi, whom can I  reach out to in my townhome assocation work was done and wires were cut underground. Xfinity sent people out to run some new lines but they forgot to run one of them.  That line is a short unndergorund run 20 feet from one pedestalto another pedestal. The wire was cut and spliced 2-3 times during the work and the linesman said that it should be replaced.  All the others that needed too were.  What can be done to resolve this.