Please, disregard my mod status here. I am writing this as an ordinary player.
First, I don't buy much, but when I do I use PayPal (Kabam also offers their own interface). This is not just for the P:ToF, but whenever I pay for something, if PayPal is an option, I use them. The key thing is: I choose to trust that one widely known and security-wise well respected company (that promptly and efficiently handled one attempt of fraud I had against my account there), and I have no interest in finding out if Plarium or any other company can be trusted, unless I really have to. When paying via PayPal, all the relevant info is handle by them and them alone.
Second, on Kabam, no payment details are handled by Plarium. I don't know which are the options are available to you guys, but I'm guessing you have a non-Plarium option.
Third, I think there is a lot of misunderstanding here about security. I have no more info on this than you (hence the "disregard my mod status" disclaimer above), but it seems to me that there is an agreement here that a group of players is using bots. However, what is misunderstood here is that bots are not magic, nor do they crack anything. They simply automate tasks, which is almost the same as having live players.
The difference between a bot and a live player is that a bot can't be bargained with. It can't be reasoned with. It doesn't feel pity, or remorse, or fear. And it absolutely will not stop... ever, until you are dead! ;-) This means that the only real abuse with bots comes from running a huge amount of alts, that a living person would be unable to run.
Now, this is an abuse worthy of swift action and harsh punishment, but it is not a security vulnerability, and - from all that was said by you and Plarium on this issue - I have a feeling that this is exactly what is happening here.
All that being said, I agree that Plarium needs to handle this far more efficiently, but they also need your reports to do so. Should you, paying customers, be bothered by these reports to Support? No, you shouldn't, but as long as it's the only way to get anything done, you have to... or suffer the consequences, no matter how unfair all this is.