Registering with the Maintenance Enforcement Office (MEO) means that the payor should not be paying you directly, because then the MEO cannot monitor how much money is owed.
If, for some reason, the payor does pay you directly, please write or fax the MEO immediately. Explain how much you received, when it was paid and how it was paid (by cheque, money order, etc.).
After you register, it cannot be guaranteed when you will receive payment as each case is different. Money has to be deposited in your account, either voluntarily by the payor or through a successful enforcement action, before it can be paid to you.