Here are the terms for the $300 processing rebate, from Square's Terminal web site:
Save money when you switch to Square.
If you’ve signed up with Square in the last two months, you're eligible to receive $300 in reimbursed processing costs after you activate your new Square Terminal.
In other words, you'll pay the full $399 today, but after you start accepting credit and debit cards, the $300 credit will be deposited into your account over time. Before long, you'll have paid only $99 in total.
For new sellers purchasing Square Terminal. Valid for $300 in reimbursed processing fees for card transactions. Processing credits expire upon full redemption, 180 days from the date of Terminal activation or 365 days from the date of your purchase if you have no card transactions, whichever comes first. Processing credits may take up to two weeks from your first login to Terminal to be issued to your account. Processing fees are reimbursed to your account with each deposit. After credits expire or are fully redeemed, standard pricing will apply. Not transferable or redeemable for cash. Limited to one redemption per customer, even if multiple Square Terminals are purchased. Square may modify, revoke or cancel the offer at any time.
I've bolded the relevant text, which suggests at least that the credits begin as soon as you activate your Terminal. If you're not seeing your credits yet, I'd suggest taking a look at the Deposit reports in the Dashboard, and your bank account to make sure you're not just missing them. If they really aren't showing up, you need to contact Square support:
You'll need your customer code to call. Follow the instructions below on how to get it.
Go to Square's support page.
Click “More”
Click "I don't see my issue"
Click "Call Support"
Write down your Customer Code
Call 1 855 700 6000
Judy T Shumway
