If your village hall has a committee (assumed since you reference chair and vice chair, also assumed that it has a form of annual meeting to validate committee and positions within the committee) does it have a 'complaints policy?'
If it does, follow it.
If it doesn't, maybe a committee (or part thereof) assessment of the grounds and substance of the complaint followed by a response to the PC.
From the very brief description it is also assumed that your wife may have been interpreted (by the PC) as being 'critical' of the PC.
There is absolutely nothing inherently wrong in an individual expressing a personal opinion about a PC - whether that be positive or negative - maybe the PC think they are akin to the PDRK or the Chinese Communist Party and are above critical comment.
Is there a PC resolution / minute to support a formal correspondence from the PC to the chair of the village hall? If not then it is not representative of the PC.
Either way, there is the option to respond or simply ignore...