We were out of the country when our furnace stopped working. My kids were at home and we called Mark to see if he could stop in and have a look. We have used him before and were happy with his service. Mark was able to come same day and resolve but when our credit card was declined he threatened my son and told him he was going to remove the part and leave. It took approximately 5 min to get in touch with us and verify the card number which was incorrect. Completely unprofessional.