How do i register a deposit for a service which will be eventually refunded?

Thank you for posting here in the Community, @lele1. I'm here to help and guide you on how you can claim the refund in QuickBooks Online (QBO). 

When you receive a refund from a vendor, you can record it as an expense or check posted to an asset account, then for the refund create a deposit posted to the same asset account. I'll show you how to do it.

1. Go to the + New menu.
2. Select Expense or Check.
3. Choose the name of the customer.
4. Select the same bank account used in processing the refund.
5. In the Category Details section, choose Accounts Receivable.
6. Enter the complete details.
7. Click on Save and Close. 

Then, let's deposit the money received. 

1. Click the + New button.
2. Choose Bank Deposit.
3. Go to the Add funds to this deposit section.
4. Enter the reimbursed amount and choose the appropriate account.
5. Add a memo as needed, then click Save and close.

The detailed steps in the article will help record the transactions specific to the expenditure: Pay for personal expenses from a business credit card or bank account in QuickBooks Online. 

Once done, you can reconcile your account to make sure they match your bank statement. 

Please don't hesitate to contact me with any follow-up questions about the recording process. The Community always has your back.