Tax Refund

Hi. Good day. I would just like to ask for assistance regarding tax refund. I was advised by one of our HR Executives that we won't have any Tax Refund this year because we (company) are already using an automated system, which she says that they are computing all the taxes or deductions correctly because of the system that they are using. For me, it is till subject for human error. Because of accuracy and all the other factors that can contribute to inputting data in a particular system. Also, can you please enlighten me about employees who had previous employers and moved to a different company within the same year is also eligible for a tax refund? I would like to know from a legal perspective along with the alignment and compliance in our law. Thank you.

anyone who had a higher withholding tax amount than what is his income tax payable is eligible for tax refund.