Do I understand you right? He offered you the money back? The whole fare or just a hundred $ ?

In my opinion, if he offered you your money back, that means the whole fare. If this is correct, then grab it ASAP as this would probably be the best you'll ever get as far as apologies are concerned. With most airlines you'd just get a standard typed answer with a $ 20 to $100 shopping coupon at the most.

Sorry for your bad experience. Next time anything like that happens, just stay put right where you are. You'll be blocking everyone and they'll soon attend to your needs and make it clear YOU CANNOT GET UP THOSE STAIRS... They'll find you a temporary seat in a jiffy, believe me.