Is sales price sufficient to protest tax appraisal?

[Alan Feng]

I'm not experienced in protesting the property taxes. In the past I have used a tax protesting service for my property and that worked fine.

Last year I bought a new property cash down at a price that is much lower than the appraisal value from the tax office. I paid the full tax for the last year since it's already past the protest date when the deal is closed. I decided to protest the appraisal this year myself, thinking it would be easy as my purchase price would be the strongest support to assess the property value. 

So I did the protest online, submitting the closing statement (it's not HUD as it's a cash down). To my surprise, the appraisal office came back to settle it at the original assessed value, without decreasing it a dime!

I don't think it's a fair assessment so will not back out. I wonder what would be the best option for me at this time:

1. Take my closing statement with me, and present it in the official hearing
2. Contact the tax protesting company and hand it over to them

A related question I have: does it matter that I replaced the floor in the property after I purchase the property? Will I be required to list all the costs of fixing things up after the sale during the hearing?

I also wonder why it's not sufficient to just providing the sales statement when protesting?

Thank you all for your inputs in advance!