basic bandpass filter
Your denominator is wrong. It should be on this form

$$
(1-z_0z^{-1})(1-z_0^*z^{-1}) = 1-2R\cos(\phi)z^{-1}+R^2z^{-2}
$$
where $z_0 = Re^{j\phi}$.

If your goal is to block DC and create an anti-aliasing filter in a simple way, I would recommend not to use complex poles. Instead use the procedure described in detail here: http://www.dsprelated.com/showmessage/172787/1.php.

It even provides a C implementation.