Transmission Repair

I got my Honda Accord transmission rebuild at AAMCO and cost $2200, at AAMCO website, they stated they have one year warranty about one year, you can go to any AAMCO nationwide within the warranty. But at their final paper work, they stated that the one year warranty is "in this service center only". I called to them, they replied that if I want nationwide one year warranty then I should pay extra $400, I suddenly feel cheated.

The following is what they stated on their website.

"When you become an AAMCO customer, you're entitled to a Warranty that
matches the quality of the service that you receive. So when it comes to Warranties... bigger isn't just better, it's the best! And nobody has more centers throughout the U.S. and Canada than AAMCO. Each center stands behind your Warranty, committed to giving you prompt, courteous warranty service, should you ever need it.''