Best Air Distribution in Corpus Christi TX

Had a technician come out twice to put refrigerant in a unit due to a leak. The first time they charged me per pound at 65 dollars. Put 7 pounds for $460. Agreed upon no problem. A few weeks later needed just a few pounds to get through another weekend before a scheduled repair with a separate company.
And once the tech gets there I'm told a service fee that I didn't have the first time around and wasn't disclosed to me when scheduling is tacked on to the bill of an additional $129. Probably because it was a smaller job. But no one ever told me or I would have just shopped around or ended up waiting out the weekend.