Probably Honda of America can't do much. It was the dealer that fuxxed up your engine. And this bs about "we didn't replace the rods, so it ain't our problem" is just that, BS
They did the work, they were responsible for some cursory inspection of the parts.
Look for an independent shop to inspect the engine--the dealer did something wrong--life is too short for coincidences and the fact that it threw a rod after only 30 days smells a lot like rotten fish. Get them to do a written report. Have them install a used engine, too, ASAP and document the cost--it's called mitigation of damages, you need a car to get to and from work (not to mention getting groceries and toilet paper.) Don't go overboard on the engine, you only want it as good as if the engine they "fixed" had been done right--no solid platinum rocker cover, please. Because, old son, you are gonna sue. Sue for the rental car, too. Talk to the local media and picket, too.
Sue them in small claims court, btw. Alternative action is to buy another car and sue for a refund and rental costs after the engine died (probably more reasonable--reasonable counts for a lot in small claims court.)
Don't get mad--get nasty!
When they say in court, "Wha, we woulda fixed it, but he didn't give us a chance." Mention that you did give them a chance and they told you to go pound sand.
I hate this BS. Another reason for never doing business with new car dealer service departments!