Grannynannywanny, you should have a letter informing you that the WFA is going to be paid into your account. As has been said, it is probably paid in alphabetical order, mine has yet to arrive. But letter states that if not received by 23rd December then contact them.
Next year, if it continues I should be entitled to the £300 payment.
The Warm Home Discount is £140,00 paid directly to your energy supplier. It is only paid to those in receipt of certain benefits, main one is Guaranteed Pension Credit. Mine has already been paid to EDF and take off my account.