Well there's no obvious legal basis for compensation, so good luck with that. So what you seem to be implying is that they should attempt to use the media to extort compensation and to cease the investigation through adverse publicity. I find that morally repulsive.
Using the media as a mechanism to attempt to interfere in ongoing criminal investigations is an absolutely disgraceful state of affairs, and as an investigator would simply motivate me to conduct that investigation to the very best of my ability, and perhaps even more thoroughly than originally intended. As a prosecutor, if something has been found, I'd be highlighting the use of media and high profile protest as a potentially aggravating element, and demonstrative of a lack of remorse.
There is also a clear legal duty on the TOC. If they suspect they are a victim of fraud, especially numerous frauds of a similar and repeated nature, which seems to be the case here, they MUST legally investigate it, either internally or with external support, or both. Company/commercial/financial reporting laws places regulatory obligations to do so. I also suspect contractual agreements relating to the franchise would require them to as well.
You are allowed to accuse people of things, even if you can't prove it. It happens hundreds of times per day in England alone.
By all means go head on, but it only needs the TOC to find 1 definitely dodgy claim out of potentially hundreds, and the media would love that story even more, the media don't like being taken for a fool.
As for politicians, I'm constantly repeating myself, but they cannot and should not intervene in live criminal investigations or subsequent proceedings. So, I'm not sure what purpose that serves. It's more logical and probably less frustrating to take it up with your MP after the matter is resolved.