Three months is not enough time to get a good sense of any kind of SEO. As EGOL mentioned it is important to look at how much you are paying them. It is also important to question what they promised you.
If any SEO company is promising you rankings of certain positions you may want to step back from them. The key is the strategy you want to use. If you are looking for results in the immediate then running a PPC campaign is the best strategy while optimizing your website. It is also important to clarify your advertising. If you offer something for free but need a credit card for whatever reason you need to express that or people are more likely to not complete your form as they feel slightly lied to.
If you are wondering what to do in terms of .com or .co.nz then the question is where is your traffic coming from and where do you want it to come from. A .com has the ability to rank globally but a .co.nz will be heavily localized to New Zealand. In this instance it is more about your goals as a company.
SEO should be a long term strategy that includes a full mix of SEM techniques to better your results. If you are not in it for the long haul you are wasting your money