Ahh, what you're hearing is actually "저기요!". If you look on some online dictionaries, they will probably tell you it means "hey!". 저기요 is used when trying to get someones attention. For example, If you're locked in a room, you'd yell "저기요!!!!!". Where as 실례합니다 is used when you've done something wrong, like barging into someones room while they're in it, or listening in on a conversation. And the third is 잠시만요, you use this when actually excusing yourself from something, for example, excusing yourself from the dinner table. :) Hope I helped!