Carers allowance when is pay assigned to a week

I have a problem with DWP in that I applied and was awarded carers allowance from 15/02/2021 but the earning rules are not very clear. In brief I calculated how much to pay into my pension in order to remain under £128/week and this is fine with DWP but my pay is paid every 4 weeks not weekly. To make matters even more complicated any extra payments from my employer are paid in the following 4 week period not the current period only basic hours are paid at the end of every 4 weeks. Every thing was fine initially but then my employer introduced a holiday pay uplift to account for historic extra hours worked and I received an extra £4 when I had a weeks holiday. DWP say that this means I do not qualify for carers allowance for any of the 4 weeks when the extra was paid. My argument is that it should only apply to the one week of holiday pay in the previous 4 week period.
I guess my first question is when is the pay allocated to a particular week, when it is earned or when it is paid?
I have all my time sheets from my employer to prove when I was on holiday or worked extra hours etc and although my employer has been very supportive they say that holiday uplift must be paid whether I want it or not!!
Today I received a letter from DWP saying that I did not qualify for carers allowance since 09/05/2021 because I had breached the earnings limits.

Hello & welcome Karen

From the above link …

At the moment, the earnings threshold is set at £128 (2021/22) per week after deductions. If you are even just £1 over this limit, it’s possible to lose 100% of your Carer’s Allowance.

Take advice from your local Citizens Advice.

The Carers Allowance rules mean you can reduce your income for CA purposes by various things like pension contributions, child care costs etc. Find out more about these.