Many thanks for your patience. Under law you are entitled to take either one or two weeks ordinary paternity leave (OPL) within 56 days of the birth of their child.
During OPL, employees are entitled to benefit from their usual contractual terms except for those terms relating to remuneration. Instead they will be paid Statutory Paternity Pay at £139.58 a week or 90% of their average weekly earnings (whichever is lower).
If they have paid you the SPP for 2 weeks instead of 1 week, which meant that you had not been paid your usual pay for the second week, then that would likely amount to an unlawful deduction of wages.
You should have been advised of that at or before the time your pay was processed especially as the law requires the employer to provide details of any deductions to be made from each pay packet.
If they have failed to return the money owed then you can consider taking the matter further. There is probably no point in taking legal action if the adjustments are made in the next pay or even the one after but if it appears that this is not going to be resolved then you can take this down the more formal route.
This is your basic legal position. I have more detailed advice for you in terms of the options you have to take this further if the matter remains unresolved, which I wish to discuss so please take a second to leave a positive rating for the service so far (by selecting 3, 4 or 5 stars) and I can continue with that and answer any further questions you may have. Don’t worry, there is no extra cost and leaving a rating will not close the question and we can continue this discussion. Thank you