I opted for the free service, personal taxes is simple, my receipts are straight forward T4 and pension income, how come when it came to filing,shows need to pay $19.99?

If you mistakenly upgraded or added a feature to the FREE TurboTax Online you started using, there is no way to remove this from your billing. You will need to start your return again using the FREE version and be sure you don't add any other features or upgrade.