I went in-person because SQ changed the time of my outbound. I was trying to use this as an opportunity to change my departure date by 2 weeks to match my revised travel plans. For my new departure date there was no award space, only revenue. So, I went in person to request they open up revenue space for me, as they changed my original departure time. SQ said they could only do that if my new departure date fell +/- 7 days from the original date of flying. I knew this was their policy but was trying my luck. They couldn't help me on that so I had to change my city of departure from where they did have award space.