Hoping someone from a HR background here. I’ve been in my current job for 18 months working 25 hrs a week. My salary is pro rota based on a 40 hr week. New girl starts (inexperience 20 year old) been paid the same basic salary as I am but her contact is 40 hours a week as she is full time. Well the HR manager has screwed up in the her contract, she’s been paid for 40 hrs a week but her working hours only equate to 36 per week.My main annoyance is that A)she’s been paid for 16 hours a month she doesn’t work B) she’s lazy and doesn’t pull her weight. I’ve raised this 2 weeks ago with the COO, he’s investigated it and realises the HR person who drew up her contract hasn’t realised she only works 36 hours and not the 40 states on the contract. Where do I stand with this? Can they amend her contract to pay her less or increase mine? They have said we should be earning the same rate. They are slow in getting anything sorted but I feel so irritated I do most the work whilst she sits playing on social media on her phones whilst been paid for hours she doesn’t work! How does a HR manager make such a huge mistake!