So here is my experience:
My friend drove me to lacolle/champlain border. We left around 9:30 from Montreal and it took us approximately 1 hour to reach the border. My friend took the last turn to stay in Canada while I walked to the US border. There was a lot of congestion for cars at the border and it was taking them a lot of time. I was the only one walking so it was kinda scary. All this time I was waiting for someone to ask me to stop and question me but no one did so I kept walking. At the US border, I walked into the line that said nexus since it was almost empty with just one car before me. I stood at the checkpoint and the guy at the checkpoint asked me to come. He asked me what do I need and I told him I am here for flagpolling. He gave me a refused entry document but the document also quite clearly stated that I had been allowed to withdraw my entry to USA with stated explanation of submitting documents to CBSA. Another security officer walked towards him and said "You got another flagpolling. It's the flagpolling day". So apparently a lot of people were flagpolling. He then told me the way back to Canada and asked me to keep walking north.
I took the same nexus line to walk back to Canada and similarly it was almost empty. At the checkpoint the guy asked me if I am bringing any goods from USA or more than $10000 cash, I replied no to both. He gave me a yellow slip with some stuff written on it and pointed me to immigration building and it's entrance. I entered and a guy at the immigration called me. He submitted my documents and told me someone will call me when my turn will come. There were already quite a few people waiting at the immigration centre at that time. In around 10-15 minutes another officer called me and asked me to sign on both the COPRs and asked me to write my address, telephone and how much money i have to establish myself in Canada on piece of paper (she didn't check any document though). I did as she asked and then she asked me if I have any goods following me etc. I said no. Then she asked me to wait. She took another 10 minutes or something after which she again called me and quickly told me my rights and I need to renew my SIN and health card. Then she told me I will receive my card on the address I just provided. I told her that I am moving at the end of the month and she got a bit rude on why I gave her the other address and that she has already added my address to my file. I told her I gave her my other address because I thought she was asking my current address. Any how I was polite and I requested her to update my mailing address to my office address which she said she will do. But she was really grumpy and in a rush through out the process. I guess it probably was a flagpolling day and they were getting too many people for immigration or she was having a bad day. Any how all in all it took around 40 minutes since the moment I got of my friends car to get back to the car. Mostly it was quite methodical and everyone at the border knew how to deal with this which made it really quick.
It's been almost 2 weeks since I called CIC and they haven't called me back yet.
