My DIY duct cleaning meant I wanted sealing

I had the dumb method of cleaning our own HVAC duct, and my hubby got myself and others a pole with different ends on it for our birthday, however i have an end that is a poof that is meant for taking down webs.

I have an end that can clean windows, dust ceiling fans and clean corners in the ceiling.

I used our ceiling fan dusting end and figured it could serve as a HVAC duct cleaning tool. I noticed webs on our vent covers. I knew inside the ducts had to be icky. I took down all the vent covers and shoved our pole up in there. I truly went to neighborhood scrubbing. I felt so accomplished when I saw the gunk that came off on our end. I truly was proud of myself until a few days later. I noticed our AC just never turned off. It kept running and running however the beach house was hot. I called a Heating and A/C dealer and the girl told myself and others I must have messed up with our HVAC duct since our method was fine. I then called a HVAC duct dealer who informed myself and others that our duct had a tear along a seam, apparently while I was cleaning the ducts I was too serious and finished making a seam, then she then performed HVAC duct sealing in order to patch the hole for me! While she was there the girl showed myself and others the inside of our ducts. I was shocked to see it was filthy. My pole didn’t get truly deep in the HVAC duct. I only cleaned an inch or two inside. I am never going to clean that myself again.