I can tell you a new "aftermarket" catalytic converter is required to meet EPA emissions standards for 25,000 miles. Have you contacted the people that installed it? I would hope they would stand behind it.
Also, the 25,000 miles is a requirement by the EPA. That isn't something that the manufacturer can change. I doubt you put 25K miles on it in a couple of months. LOL
Here is the only issue I can think you may have. The vehicle has a warm-up catalytic converter in the exhaust manifold and then another converter under the vehicle. See pic 1
If the same one has failed again, we need to check a few other things. For example, high fuel pressure can cause a rich fuel mixture. That can damage a converter. Also, even an engine coolant temp sensor can cause issues because it indirectly controls the air-fuel mixture.
I don't know if you have any interest, but the remaining pics below are the directions for the removal and replacement of the converters. I figured I would add them in the event you want to do it yourself.
Let me know if I can help.
See pics below.
Images (Click to enlarge)
Saturday, April 17th, 2021 AT 9:54 PM