I feel like I've accidentally become 7 years old again.
From 2014-15 I worked with a colleague. Let's call her Sandra. i had a lot of time off during that period with my mental health, but Sandra and I always got on well. I moved away, and we didn't stay in touch, but we're on Facebook/twitter with each other.
About 6 months ago she blocked me on twitter. Fine. She then deleted me as a Facebook friend. Fine. We hadn't been in touch since stopping working together and it didn't bother me, other than slight interest when I heard she had left our joint previous place of work.
Today I went to the main head office for work and she was working on reception. I greeted her warmly, said it was nice to see her. She ignored me to the point of one my colleagues commenting.
When I left, I tried to chat again to her. She was frosty but polite so I said "it was such a long time ago we worked together, maybe a coffee somewhen would be good". She then said "I'll see you when hell freezes over".
I was shocked, and said that if I'd upset her then I'd rather talk about it and clear the air. She ignored me.
I have to go to this office every few weeks and I'm now feeling concerned that it will be awkward each time with her. She is clearly angry at me, but I don't know why, or what I can do to fix it. Any suggestions?