"하이고마, 내 정신 쫌 보그래이 손님을 세아놓고...미안하데이" (this is in nonstandard dialect).
= 아이고, 내 정신 좀 봐, 손님을 세워 놓고 ... 미안해요 (standard modern Korean).
= Oh my gosh, I'm so out of it, keeping a guest/customer standing. Sorry about that.
* 세우다 = 1) make a person or a long object stand upright, 2) stop a person or thing (from a moving state). It is a causative verb of 서다 (1. to stand, 2. to stop).
* -아/어 놓다 = put/leave in a certain state.
* 세워 놓다 = 세우다 + -아/아 놓다 (우 combines with 어 to become 워) = to make/keep/leave someone/something standing.
So it means to keep someone standing there instead of ushering them in or offering a chair, etc.