  In our previous work [18] we constructed a model of a noncommutative, charged
and massive scalar field based on the angular twist. Then we used this model to
analyze the motion of the scalar field in the Reissner-Nordstr\"om black hole
background. In particular, we determined the QNM spectrum analytically in the
near-extremal limit. To broaden our analysis, in this paper we apply a well
defined numerical method, the continued fraction method and calculate the QNM
spectrum for a non-extremal Reissner-Nordstr\"om black hole. To check the
validity of our analytic calculations, we compare results of the continued
fraction method in the near extremal limit with the analytic results obtained
in the previous paper. We find that the results are in good agreement. For
completeness, we also study the QNM spectrum in the WKB approximation.
