Congratulations! A 126 signal is pretty good in most areas.
Likely the post was never pinned at the bottom to prevent turning in the concrete, or there wasn't enough concrete poured to prevent it from turning in the dirt.
If you're inclined, you may be able to stabilize that pole by cleaning the dirt from on top of and around the old concrete at the base of the pole, drilling a hole through through the post an inch or two above the old concrete and inserting a bolt through the hole (this prevents turning), and then pouring 4 sacks of readi-mix concrete (about 2.5 square feet) into a 2' X 2' X 6" square wooden form surrounding the concrete and the base of the pole. This will lock the pole into the new concrete. Make sure you protect the cable and crown the wet concrete so that it sheds water away from the pole.
NOTE: If you're in an area prone to frost heave, then you should build the form narrower and higher so a heavy frost underneath the new concrete won't lift the whole mess out of the ground.
This will take some work and you may want to wait for the tech to come out.