Firstly, were you allowed to try things on? Because of coronavirus, many shops will not open the changing rooms and ask you not to try on items. Were you allowed to do that here or were the shop assistants trying to ask you to stop?
If you are in the right, then no, nothing will be done as you reported it to a completely different store. There was no formal complaint made, and the shop you spoke to has no evidence of the incident occurring because you’ve made it simply your word against hers.
If you want to go through the effort of “getting her fired” as you say, you’ll have to do a lot more. A formal complaint to the shop manager, contacting customer service etc. However, unless you have accurate recollection of the event and the shop assistants identity, not a lot will happen.
And don’t bother police with this. It’s not a criminal offence and just seems silly to try and involve them when they have more important things to look into