I have bought a part from a supplier and wasn't needed the supplier has refunded me what do i log this as on my banking?

We can easily record the refund amount in QuickBooks Online, jimwagen.

First, we'll create a supplier credit to show that you've returned the item:

1. Click the + New button and select Supplier credit.
2. Enter the Supplier and the Payment date (refund date).
3. Go to the Item details section and enter the item in the PRODUCT/SERVICE column.
4. Enter the refund amount in the AMOUNT column.
5. Click Save and Close.

Second, we'll record a bank deposit to show that the supplier refunded the amount and affected your bank.

1. Click the + New button and select Bank deposit.
2. Enter the bank account in the Account field.
3. Enter the deposit date and go to the Add funds to this deposit section.
4. Select the supplier under the RECEIVED FROM column.
5. Select Creditors in the ACCOUNT column.
6. Enter the refund amount in the AMOUNT column.
7. Click Save and close.

Lastly, we can create an Expense or Cheque to link the two transactions.

1. Click the + New button and select Expense or Cheque.
2. Select the supplier in the Payee field and enter the Payment account (bank account).
3. Enter the Payment date.
4. On the right side of the Expense or Cheque window, the Add to Expense or Cheque drawer will appear.
   Click Add on the Deposit and the Supplier Credit.
5. The Deposit will appear under the Outstanding Transactions section, while the Supplier Credit will show under the Credits section.
   Ensure the AMOUNT PAID in the upper-right corner is 0.00.
6. Click Save and close.

You can also use this article for reference: How do I handle supplier credits and refunds?

I believe you can do this with ease. Have a great day!