Name change.
Good friend who I've known 15 years. Never a cross word between us and I've done a lot for her when times haven't been great.
Made a thoughtless comment to her a couple of months back. Realised straight away that I'd upset her so dropped a card in next day to say how much I valued our friendship and hoped she would forgive me for being so thoughtless. Also apologised to her next time I saw her, although she was obviously sulking.
Been away most of the summer and thought she would have got over it by now. Couldn't believe it when I saw her in town this week and she completely ignored me when I said hello. Spoke to her DP today who talked to her. Apparently she will stop sulking "when I've apologised properly". 
AIBU to think that this is just control freakery on her part, tell her that I have already apologised and say WTF do you expect me to do? Or do I send another card? She won't answer the phone to me and ignored a couple of texts I sent while I was away.