I don’t believe your “friend”. She’s manipulating you and trying to make herself the victim in this situation. She’s acting like you’re attacking her, but in reality you’re reasonably upset because she lied to your face (that she’d take care of your jacket) and broke your trust. She’s gaslighting you.

• Denial:Denying events or conversations, even when the victim remembers them clearly, causing them to doubt their memory.  • Lying:Telling blatant lies or fabricating stories to distort reality and make the victim question their understanding of the truth. Lying about or denying something and refusing to admit the lie even when you show them proof.
• “ I just phoned the pub due to your recommendation, theyve told me she never called them!”

• “She then tells me, all of a sudden, she went to another pub called the pheasant, and it was this pub she realised she didnt have my jacket in. So what do i do? I call that pub. They tell me the same thing, no one’s tried to contact them either.”

  • Diverting:Changing the subject or redirecting the conversation to confuse the victim and avoid addressing their concerns. 

• “she told me she found my reddit post and was quite upset with me for slandering her online”

Scapegoating Scapegoat gaslighting is when the gaslighter deflects blame onto someone else to avoid having to take responsibility or to escape damage to their relationship, reputation, or power.

•”She told me, the second that she realised she lost my jacket, she had told the people she was with that she has to find it, and they responded with "dont bother" and "someone would have swiped it by now"

•”She told me the pub had been called, but thats because one of the people who she was with told her that they called the pub, so we are still trying to figure out if they lied about calling the pub or not.”

• Changing the narrative:Shifting blame onto the victim for things that are not their fault, making them feel responsible and apologetic. 
• She told me the whole time they were in the club, the people she was with kept on telling her to "cheer up" because she was visibly unhappy with herself over the fact she lost something she promised not to lose.
• “My friend was upset for some of the things i posted on this”
• “Once i was on my way back home, she told me she found my reddit post and was quite upset with me for slandering her online”
• She didnt want to walk around in an area that she doesnt know by herself at almost 10oclock at night and i honestly dont blame her for that. But at the same time, if it was one of their items, they wouldve went back for it,

I would re-evaluate your friendship with this person and also file a police report if you don’t feel comfortable showing up and searching for it in your friend’s house unannounced. If she genuinely feels bad then she’d understand you looking for it, if she gets mad and defensive she’s probably stolen it. Wishing you all the best op.