I would do exactly the same as you however.....

I would not say sorry I would phone her up and talk as if nothing has happened and if she does it again then have a go at her again ! Let her storm off and sulk or whatever she wants to do to get over it lol....

Then phone her again and act as if nothing happened.

If she gets angry with you down the phone say in a loud voice ' I am not going to say sorry as I stand by what I said now I am going I will call you later ' then put the phone down.

I would continue like this until she gets the message.