Please know that this isn't the kind of service we want you to experience. But I'm here to help make sure that you can import your account transactions and get you back to working order.
You can consider setting up a test account to import your account transactions. This way, we can determine if the original account is corrupted.
If you can successfully import the transactions into the test account, you can merge those accounts to your original account. Here's how:
From the Chart of Accounts screen, locate and select the old account.
Choose Edit at the bottom and rename it to the correct bank's name.
Hit Yes when prompted to merge the selected accounts.
Click Merge Accounts to confirm.
You don't need to worry about merging accounts since it will not remove your previous reconciliations. For your reference, you can read this article for the detailed information: Merge Accounts, Customers, and Vendors.
Also, I've already informed our support team so they can directly help you import your account transactions in QuickBooks. Thus, you can expect a callback within the day or on the next business day.
Please don't hesitate to get back to me if you have any other concerns. I'll always be ready to help.