Thank you (kam sahm nida) dropped syllable?

Ok, I've heard at least 100 native Korean speakers say 감사합니다 (gamsahabnida) now and it seems to me everyone drops the third syllable hab in kam-sam-hab-nida. To my ear it sounds like two syllables with the “nida” (nee-dah) suffix or kam-sam-nida or, possibly, kam-sab-nida, which is much easier to say, frankly. I know we have similar examples in English, such as “memory” which is usually truncated to “mem'ry" rather than pronounce all three syllables mem-or-ee. Any native speakers who can help me out here? It's such a common word I want to use it correctly.