neobux: I've lost referralsReferrals

may disappear from your account based on their type (direct or rented) and based on some other factors.

If a direct referral disappears, it can only mean that the referral's account was permanently suspended. As it would be redundant to have an inactive referral, he/she is removed from your account.

If a rented referral disappears, it can only mean that the rental expired.
Rented referrals have a due date that must be met so that they continue to be yours.
Even using AutoPay, you need to be aware that if their due date falls behind the 20 days (or less in certain Golden Packs), AutoPay won't be triggered for those referrals thus not adding another day.
In any case, you need to extended their rental before it ends.