Before trying to restore from backups, could you open the Azure SQL logical server using Azure portal, and try to restore the deleted database? See image below:
If you cannot restore the database using Azure portal, try using the following PowerShell commands:
PS C:\>$DeletedDatabase = Get-AzSqlDeletedDatabaseBackup -ResourceGroupName "ResourceGroup01" -ServerName "Server01" -DatabaseName "Database01"
The above command gets the deleted database backup that you want to restore by using Get-AzSqlDeletedDatabaseBackup.
Now, the next PowerShell command starts the restore from the deleted database backup by using the Restore-AzSqlDatabase cmdlet. If the -PointInTime parameter is not specified, the database will be restored to the deletion time.
PS C:\> Restore-AzSqlDatabase -FromDeletedDatabaseBackup -DeletionDate $DeletedDatabase.DeletionDate -ResourceGroupName $DeletedDatabase.ResourceGroupName -ServerName $DeletedDatabase.ServerName -TargetDatabaseName "RestoredDatabase" -ResourceId $DeletedDatabase.ResourceID -Edition "Standard" -ServiceObjectiveName "S2" -PointInTime UTCDateTime.
Hope this helps.