Office Planner interview questions

Was interview at online via Zoom. On that day notified via email that I am shortlisted. But on that day I replied email back whether what is are the benefit and all. I will assume the person who email me is HR she didn’t reveal much she only say medical leave and annual leave. Which I am like okay never mind maybe I will drop by and ask more questions before I sign the offer letter. Who knows when I went down to sign the offer letter it actually indicated that I need to give a 3 months notice if I tender. So I did ask further why is there a 3 months notice ? The HR who attended to me she couldn’t explain clearly why is 3 months notice she just mention this is the latest SOP for all new staff who going join or joined. So I told her hope that it can negotiate for the notice period as much as I want to join. She say she will talk to management. Afternoon email comes in accounts manager couldn’t explain why is there 3 months notice and keep saying that it is the new SOP. And after that she just say the position is taken. Please make clear to candidates who are shortlisted for the position what are the pro and cons of the offer letter. And not hidden things like 3 months notice. Make clear to both party and be honest. Candidate specially make the trip down from north east to pasir Panjang.