Big Tex A/C - Austin, Inc

We purchased a new home in November 2012. We do an annual check of A/C and Heating and had our guy go up in the attic to inspect. He immediately called us up there and pointed out some issues. He did no work and came right back down. We went in the attic and took pictures so they could see the damage. In a few days a technician came to install a coil (his words) but came back down from the attic because there was missing installation and he could not install. A few days later another technician came and replaced a huge piece of duct work but did not install a new coil. This was done under warranty (after our AC person had been in the attic and the warranty was supposedly voided.) This weekend, the unit was not cooling and I called for service. When the technician came this morning, he said he could install the part and cover the cost of the part but would have to charge us for labor--would not labor be covered under warranty since part was covered??). We called and spoke with [redacted] and he said because we had another AC company inspect the unit, it voided our warranty (even though this AC person did NOTHING.). [redacted] insists the warranty is no longer valid because he cannot trust that our AC guy did not do any work. I feel like [redacted] is penalizing us because we did not call him to inspect our AC. He is unwilling to continue our warranty.