Auto Repair Warranty Question

I had my transmission replaced at 96,000 miles. I took it back a year later when it was still under warranty at 115,000 miles and they had to make some repairs on the transmission. Now my transmission is shot at 124,000 miles and the repair shop is saying it is out of warranty (it was a 2year/24,000 miles warranty). Does my warranty start over at the time of the repair or does it stay from the time it was 1st replaced?