Overpaid by employer

I was overpaid by my employer due to salary not being pro rata ed. As an employee I was advised that this should adjusted through payroll using the gross figure. I have now left the company and there is money still owed but should it be recalculated at net? I can't get my head around repaying money that I haven't been paid. I had 3 tax refunds through my payslip but they all went to bring down the over payment amount.

Hi marckus hyde,
You would need to contact your employer to discuss how the overpayment of salary will be repaid. 
Thank you. 

Thank you. I am unable to get any clarity from them and no longer work there. I am looking for what would be correct procedure when an employee leave as it feels like I am paying back money I haven't had, and as I am no longer in their employment, payment cannot be made back through payroll with tax adjustments

Hi marckus hyde,
As this a overpayment of wages it would need to be with the employer that you discuss how this will be repaid.
If you are disputing the amount to be repaid you can contact ACAS for assistance:
https://www.acas.org.uk/advice
Thank you.