how do i get my money back of these people who you cant reason with.?

[........]

ok so this friend of mine brought me and my mate tickets for a concert and her mum was taking us(we paid her for the tickets),it has been 3 months so i asked her on facebook if she had the tickets because she hadn't told us if she'd even ordered them,some how that seemed like i accused her of stealing my money so her mum wants me to apologize to her despite the fact i did nothing wrong,also the friend who brought them was pissed of with my mate because he didn't invite her to his party,so im not apologizing to her mum so instead i asked for the money back for the ticket but she said that she'll give the ticket but not the money,is their any legal advise you can give me that i can threaten her with ,any thing will do because her mum smokes weed so she won't want to get involved, also it may be helpful to know that the girl who was taking us and brought the tickets is used to be the center of attention and her mum is the type you cant argue with.
ok basically me and a friend fell out i was going to a concert with her and a mate and now she wont give me my money back

[Elisa]

What?

[Maria]

go to citizens advice and take it through small claims court