Based on the policy manual, they don't have grounds to take away February's commission, from what I currently understand.
It states that they can take away commission during the fraudulent period. How long is a "period"?
At this point, that appears to be one contact. Do they have evidence / proof of anything more than that? If so, then they could make a case for the "period" between those two contacts. If not, the "fraudulent period" is either that one sale, or perhaps that one day (since your goal is X contact per day). They'd be hard-pressed to justify extending it to cover the full month IMHO. Not that they wouldn't... but they'd need to clarify things.
If you've got a lawyer friend who could review things, it would probably be worth your while to do so. Policy manuals aren't often reviewed by lawyers... my company's manual specifically states that nothing in it is legally binding

Great way to say it is just a suggestion
Even if you have to pay the lawyer, I suspect it will only an hour or two. That's probably a lot less than the commission amount at risk.
Hmmm... as I think about this here, let me state a couple of things that *you* could state that put you in a good light.
- You have to make X phone contacts / day
- Some clients insist on email, not phone
- The confirmation collateral is system-generated and you cannot change it
- It assumes that all contacts will be by phone, and doesn't consider email
- One email customer received one of those and brought it to someone's attention
- You logged that email contact as a contact
- When the policy was crafted, were email contacts a normal part of business? Or was it crafted before email was a common part of everyday business life?
- Policy dictates it's not a contact, but it's what the buying customer wants. What's right? Policy or the customer?
- Policy indicates that commissions can be withheld for fraudulent activity.
- Is "fraudulent" defined anywhere? Here is one legal interpretation that addresses the fact that "fraudulent" is often not well defined, leading to use of commonly accepted standards for fraud, which he explains.
- The definition of the fraudulent period is also unclear. That sale? That customer? That day? That month? Where does it state what the period is?
- This leads you to a good question to ask them... why is it fraudulent? You consider it an honest mistake, and one that you certainly won't repeat.
- When all is said and done, the purpose behind things like call targets is to ensure a rep is making enough calls to be able to hit their numbers. You're not only hitting, you're exceeding. Consistently. Where are the damages to the company?
- At the end of the day, there are a couple of issues. The company's systems don't apparently address those clients who don't want to be contacted by phone. You are finding ways to take care of your customers that walk within and around the existing policy. And as you do so, you're exceeding the targets the company sets for you.
- Is it better to target you, or to target someone who's *not* meeting the sales targets being assigned by the company?
As for your former manager, you could still drop her a line asking for any suggestions on how to handle things. She may side with the company, but she can also be a valuable resource for you as you navigate this. She may be able to tell you how to end up with a general win across the board. Or she may run straight to HR and let them know she's been contacted. You'd know her better than anyone here... your call. Personally, I figure any possible ally is better than none.
BTW, I wouldn't be inclined to role-play during a dinner party. I think this is more important than that... you need to put some really focused efforts into it, and with someone who can play the company heavy as well as giving you constructive feedback about it. I don't think I'd be able to do that between the main course and dessert....
Good luck. You've got a lot of stuff to do between now and tomorrow's meeting.