Make some hand-outs explaining how AAMCO destroyed your trans and how they are blowing you off now. Be professional about it and hang out in front of the store some busy Sat. Warn the patrons and suggest them to go elsewhere. The last thing a business needs is someone shooing away the customers. I've returned used cars this way. You may get bullied but don't leave till they call the cops. And if they touch you it's assault. The police will come and ask you to leave - this will look wonderful for the business. Ask the police if it's okay to distribute fliers by the sidewalk/easment once they kick you off their property. This is when you'll need a picket sign (i've never had to use a picket sign but maybe someday).

If that fails get the car fixed elsewhere, ideally Honda, but make sure you check the BBB for complaints. Then goto small claims as jc836 recommends and you will win. Make sure you document everything, and get video of the car in the current condition. Have the mechanic write something on the estimate regarding what is wrong w/ the car before they fix it. Make sure it doesn't read "customer complains trans is bad" it's got to read "we found xyz wrong, and needs new pdq"

Watch peoples court for a few weeks to get familiar w/ things (judy or millian). You will need to prove your case so come prepared. Small claims has a cap at i think usually between $3500-$5000 depending on state - how much did you pay them? Courts usually favor the consumer, sometimes they may even award you punitive damages if they see that AAMCO "abused" you. Good luck!