If this is the UK, then there is a definition for Theft in Law, which states,
"A person is guilty of theft if they dishonestly appropriate property belonging to another, with the intention of permanently depriving
the other of it", so if you apply this defintion to the circumstances
you have outlined regarding the property :-
Once the owner of the club sells the stock/goods that your friend
can prove she bought, then the owner of the club has assumed
rights of ownership, the question here is, was the owner of the club
aware that the property had been purchased by your friend,then at
that instant he/she has dishonestly appropriated it, even though it does not belong to him/her, and then sells it, has permanently deprived your friend of the property.
With regard to the rest of the money owed, if the club has been put into receivership, then your friend should make a claim through the official receivers to claim back the rest of the money she states she is owed.