Well, the OP seems to have been guilty of fare evasion, and breaching byelaw 10(5) for good measure.
Had the correct charges been put, he/she would, IMO, have no defence; however, the magistrates can only rule on the specific charge before them, and, for reasons already given, I believe that the decision of the magistrates to acquit on the actual charge brought was the correct one.
Although the six month time limit for pursuing a fare evasion charge has now passed, it is still possible that a summons issued in, or before, January (perhaps by VTEC) may yet find its way to the OP, so he/ she should not celebrate just yet.
If not, then there remains a civil debt in the amount of the unpaid UFNs, albeit that I personally consider it unlikely that VTEC, Thameslink, or any other TOC, would seek to pursue the debt in a county court. The validity of the PF is no longer relevant, since it was cancelled in order to pursue the failed prosecution.
Morally, the advice must be to pay the unpaid UFNs, albeit that I suspect that the practical advice would be to sit tight and hope that the matter is not pursued further.
Regardless of my personal opinion of whether the OP deserves the extreme good fortune that has come his/ her way, I do think that the acquittal shows that it is possible for a defendant wrongly charged, or, as in this case, charged with the wrong offences, to get a not guilty verdict without needing to hire an expensive solicitor. It follows logically that I believe that a passenger who is wrongly accused or wrongly charged should not simply plead guilty or pay a 'out-of-court settlement' for the sake of expediency.
