Why is TurboTax estimated Tax Refund for RRSP FAR LOWER than all online calculators?

Hi,

My case is very simple. I earn $275,000 as a full time employee in BC. I have no other income, no deductibles (other than RRSP), no child or other benefits. My RRSP contribution is $27,230. Shouldn't the tax refund on that be around $13,500 (roughly 50%)?

All online calculators (including EY and other reputable ones) confirms the above. TurboTax calculator gives back HALF OF THAT $7,308!

It's basic math.. I am at the highest bracket.. All my RRSP contribution is above the highest bracket. The highest bracket is at 53.5%.. So quick math should be around 50% refund, right? What am I missing?

Thanks, 

Sam