Doesn't matter how many times you ask, the answer is the same. While it was theoretically possible for them to be married in the Church of England if they'd found a clergyman who was prepared to officiate (since the decision about remarrying divorced people is left to the discretion of the individual clergy), it's well known that in a case where the couple were having an affair during the first marriage of either or both of them, it wouldn't be easy to find a clergyman prepared to officiate. Doesn't mean it'd be impossible, but it wouldn't be easy.
For most people, the local clergy would probably refuse to officiate. Some people would be lucky and live in a parish where the clergyman was more broad-minded, but a lot wouldn't. If a more broad-minded senior clergyman had come forward and offered to marry Charles and Camilla, it would have looked like special treatment, and this is something the royal family have tended to try to avoid over the years.
With the marriage being resented by an element of Diana fans (and yes, that does factor into the equation however much you're trying to claim that it doesn't) as well as by more traditional people who simply don't accept remarriage after divorce, the level of tolerance for an egregious case of special treatment would have been pretty low, and it would have been unwise of the royals to try and force it.
Now, if you can go through the Church of England website and quote where it says that people in Charles and Camilla's situation are prohibited from having a Church wedding, go ahead. At this point, that's the only thing that would give your claim unequivocal support. Start here
Marriage in Church after Divorce (updated February 2003) | Church of England
and also follow some of the links.