I would add that section 115(3) of the Copyright Act 1968 (Cth) (Act) may be relevant here.
That section says that:
"(3) Where, in an action for infringement of copyright, it is established that an infringement was committed but it is also established that, at the time of the infringement, the defendant was not aware, and had no reasonable grounds for suspecting, that the act constituting the infringement was an infringement of the copyright, the plaintiff is not entitled under this section to any damages against the defendant in respect of the infringement, but is entitled to an account of profits in respect of the infringement whether any other relief is granted under this section or not."
In practice then, if you try to make a claim against the new business owner for breaching your copyright, and that person is a bona fide third party purchaser (i.e. he/she bought the business and had no idea that they were infringing your copyright in the logo, and just assumed that your friend owned that copyright (because your friend probably warranted that they did in whatever business sale agreement they entered into with the new business owner)) then I would expect that new business owner to tell you that you had no claim against them, for any compensation.
Pursuant to section 115(3) of the Act, you can still be entitled to an "account of profits" but given that you made this logo for free, and were not profiting, you won't be able to establish any "loss of profit" and so I don't expect you to be owed anything for that either.
Also, I would also heed section 202 of the Act. It is not relevant yet but it might be, if you start trying to "force them to pay". That section provides that persons who make groundless threats of legal proceedings for copyright infringement can be liable for damages themselves.
Next time you design a logo, I would recommend that you enter into a licence agreement or deed (for your intellectual property). This document can set out exactly how, when and by who you want your work to be used.
Best wishes.