There's a weird power imbalance in these situations. The person reporting the problem is able to tell whatever story they want since they generally don't have a reputation to maintain (and will, if anything, likely improve their reputation), and the company has to be very careful - it's often better to not release any detail to avoid potentially worse fallout from releasing potentially private information (yes, the privacy of the person making the complaint).

This is especially bad when your company is on the receiving end, and you know the truth. For example, a previous company had someone making claims that some purchase was made on their credit card without their knowledge - but there was account email confirmation at account creation time, account email conversation with community support, actual logical proof from the post itself of something that required said purchase, and so forth. In another case, an account is closed due to some clearly provable illegal behaviour, but it was blamed on not paying to renewing something optional.

So since then I'm perfectly capable of neither believing nor disbelieving claims made by people, even when it happens to agree with what I was thinking already. It doesn't make me feel better or worse than believing them, I just assume I don't have the information necessary to make any real judgement about it. Life lesson, I guess, and useful to not get sucked into things like political theatre.