Maternity leave resignation and annual leave.

[Iwishicouldflyfarfaraway]

Hi, I'm looking for some advice/ confirmation on my situation.
Today is my last day of the paid part of maternity leave, I handed in my resignation when I was advised returning part- time would not be possible.
I gave a months notice and stipulated in it that I would take payment in lieu for the remaining accurued leave after the notice. ( I had previously checked with My manager how much had accurued up to the end of maternity leave before I was informed my request for part time hours had been rejected.). Today I received an email advising I would be paid my final salary early and a copy of my payslip and they haven't paid me my annual leave. Everything I've Google has said I'm entitled to accurued annual leave in payment when leaving. I'm just wondering if there are any exceptions to this I may have missed? .
I have emailed and advised them they have forgotten my annual leave but have had no response.
If there are no exceptions does anyone have any advice on how to ensure they pay it. I'm worried they will just not reply to emails - payroll & HR are not in the UK although the UK side of the company is registered here, so it would come under UK employment/ maternity rights.
Hopefully this makes sense thank you in advance.

[FuzzyOwl]

They might not have agreed to pay you in lieu (check your contract, as they don't have to). It could be they will pay you next month as if you had take the holiday time off work as normal.

[hellokittehhhh]

Hi, when was your last official day of emoyment and when do your holiday years run from? I only ask because in my company holiday years run April 1st to March 31st. We are entitled to 6 weeks a year, by this point in to the holiday year I wouldn't have even accrued a weeks holiday, id have to work 2 months to accruee a week. If my last date of employment were today I may have 2/3 days??

[Iwishicouldflyfarfaraway]

Thank you for your replies.
FuzzyOwl: the email mentioned they have sent of my p45 to Hmrc would they still be able to pay the annual leave next pay period?.
Hellokit: leave year is Jan - Dec . By official employment date do you mean the date on my resignation? Which is Sunday. But as its an office job last working day is Friday 13 but have used annual leave to cover the Thursday and Friday in my resignations but this isn't shown on the payslip only the last 2 weeks of maternity pay.