This bar I used to go to often is now making accusations against me?

i'm not entirely sure what they are but there accusing me of something that allegedly occurred on a Saturday night 2 weeks ago the last time i was in the bar physically.

they've provided no evidence and not even stated to me what the accusation is exactly , i've never been contacted by the police and does not appear there investigating me for anything. but the bar denied me entry when i tried to go there last Saturday. on the context something happened 2 weeks ago.

should i seek outside legal advice? send them a threatening letter telling them i'm going to get lawyer if they don't back down or at least provide some evidence , they claim to have 72 cameras watching the building so surely they know what if anything happened that night.

i'm not sure what to do , been going to bars all my life and never had anything like this happen before. i'm not sure i really care to go back there for the time being but the though i'm being accused of something i don't feel i did is not fair in my view , and i'm not even sure what i'm being accused of exactly. i recall buying an attractive younger women a drink and that seemed to annoy some people there so i think it might be related to that

Updates
+1 y
to make it clear i do NOT plan to go back to this bar anytime soon , so don't worry about that if your wondering , i was denied entry and don't think i could get back in anyways
This bar I used to go to often is now making accusations against me?
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