Hello Aaron,
Thanks for posting your question in the Microsoft Q&A forum.
You can try canceling the ongoing migration, go to your storage account in the Azure Portal. under the "Settings" section, click on "Redundancy". If the migration is still in progress, you should see an option to "Cancel" the migration. Click "Cancel" and wait for the migration to be canceled.
If canceling the migration doesn't work, you can try force deleting the storage account using the Azure CLI or PowerShell.
az storage account delete --name <account_name> --resource-group <resource_group_name> --force
Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful