I think we are "unique in the market and cannot give the reasons why" is code for: we deactivated you and we don't want to argue with you about it, so we're not even going to engage the question. Not that I blame them, if you don't want to hire a plumber again to work on your house, you don't have to give him a reason and any MSC doesn't have to give us one. But it's not like the unique reason they don't want you shopping for them anymore couldn't be explained. Even without giving away any proprietary information, they could say something like, we have too many shoppers with your demographics in your area (or whatever other vague, general reason), so we dropped some that were the most recently added (or whatever).
My point is that the company *could* explain if they wanted to, but apparently they don't. But the person you spoke/emailed with probably doesn't have the authority to give you the answer, so they were probably being honest. They might not actually even know why you were deactivated. Good luck finding other companies to work for, I expect MF will give me the boot too one of these days, so I hope you're able to fill your schedule without them.
Shopper in California's Bay Area