Panda...there was plenty else you could have done...none of this was on a timer.
I very much disagree @pictish, and that's putting aside the fact that CF1 refused to speak directly to the OP even while showing she had the capability to do so as she was messaging F2&3 at the same time she was ignoring the OP.
The OP is not affliated with the school beyond CF1, F2 & F3 having kids there. This means that her business was being advertised in a place where she has little chance of being aware, unless her friends inform her and whilst F2&3 informed her of the flyers they may not be aware of other advertising that was either in the process of being made or was already printed and just waiting to go live.
At least one round of flyers have gone out to parents (which is hundreds of families) and who knows how many other flyers were planned, not to mention banners outside the school, posts on social media from the PTA and it's members, posters both at the school and in local community spaces - especially if other parents also have businesses , adverts in local press (One of my DD's classmates' parents works for the local newspaper and another works in the local radio station so it's quite common for school events to get both printed ads and radio spots at discounted rates) etc all potentially mentioning the OP's business as a donor. The longer this goes on the more potential there is for the OP to get negative press from withdrawing the prize that she never donated in the first place
It is also now going into half term week, so the PTA probably will have wrapped up most of their work before the holiday and won't be planning to get together until at least after half term ... that's a whole week where they may not have been contactable. The OP only had the PTA Chair's information because F2&3 knew her details and so could pass them on. The PTA Chair only saw the OP's message because F2&F3 saw her at the school gates and mentioned that she had sent the message and was trying to get in contact re: an issue with a donation ... if the OP had to find that information herself it might have taken her a few days and that could have gone into half term and the message may have gone unread until after the hoilday, all the while the OP is waiting and wondering if the situation will be salvageable.
By getting hold of the PTA Chair as soon as the issue was brought to the OP's attention once it had become clear that CF1 had no intention of talking to the OP and that she had blatantly lied to the PTA about the OP being aware of the donation it meant that everyone who had any kind of power to change things (whether it was the Chair offering to pay for the CC from PTA funds, or working out a compromise or the OP making her generous alternative offer) was in the loop, was aware and could work together to come to a mutually beneficial solution ASAP.