More deductions & donations reduces my refund?

Has anyone else noticed the more/higher donations and deductions you input, the less refund you receive--is this happening to you too?  For example, in my return this year:

 

At one point in entering my data into TurboTax, my Federal refund was $1,021 and state was $253, I then entered the property tax I paid for my home and TurboTax said, "Congrats, you get a tax break", but my Federal refund went down to $708 and my state stayed at $253.

 

Next, I entered clothing and household goods donations I made to Goodwill using the ItsDeductible feature, and my refund again went down to $636 (no change to State). 

 

I then entered additional donated items using ItsDeductible for donations to ARC and my refund again went down to $564.

 

I then entered cash donations to various non-profits and with each donation, my refund kept getting lower and lower from $480, then $456, then down to $432.

 

While I'm not a tax expert, I would think more donations should reduce my tax liability, not reduce my tax refund?   Or is our tax code so complicated this reasoning isn't accurate?

 

If TurboTax's software is broken, how do we, as its customers, get compensated for their software calculation error(s)?  If any errors in their software are discovered, are we provided amended/corrected returns using the proper calculations or does their small-print liability waiver state we're just SOL?