think you should try again later at picking up time cod. Force the woman to speak to you.
I did this once with my now MIL. We went to the same hairdressers (she was trying to be trnedy not be trying to be old lady). Anyway she openly hated me at hte time so I said "hello" at the basins regardless and she blanked me, so next time our paths crossed (think I was having a shameful perm or something) in the salon I said "hello" again - again she blanked me then it turned into a battle of wits between us and I won! Ha! then I used to blank her when I saw her out.