I just changed from quick book desktop to quickbook online version and i was c harged twice for the online version for the first month

You can check your Billing and Subscription page to identify if you have a duplicate subscription under your account.
 

Here's how: 

1. Go to the Gear icon.
2. Select Account and Settings.
3. Choose Billing and Subscription.
4. Under the QuickBooks section, click on the View Payment History hyperlink.

You'll have to cancel the other subscription if you have a duplicate. Please check this article on how: Cancel your QuickBooks Online subscription or trial.

If you can only view one QuickBooks Online subscription, I'd suggest reaching out to our Customer Service Support. They have a specific tool to review your billing information and can provide more details.
 

Here's how to contact them:

1. Go to Help.
2. Click Contact Us.
3. Type your concern in the box and click Let's talk.
4. Select the Start messaging button.
5. Fill out all the information needed.
6. And click Send message.

In case you'll need to update your billing information, you can check out this helpful guide: Update your Billing and Subscription Information in QuickBooks Online.

If you have any other concerns, feel free to leave a comment. We will fill you in. Have a good day.