Agency Timesheets - how long stored for?

Hi anyone know how long carers timesheets should be kept by the agency ?
My father paid for private care / careers via the local council county and I need to see the evidence of what they have booked on the times to what my dad has been invoiced for. I think I might be fobbed off so would like to know the legal timescale
Any help would be very welcome

HM Revenue and Customs :

Your records must show you’ve reported accurately, and you need to keep them for 3 years from the end of the tax year they relate to.

HMRC may check your records to make sure you’re paying the right amount of tax.

PAYE and payroll for employers: Keeping records - GOV.UK

One’s timesheet … part of the audit process.

As for " Access " to them , the word CONFIDENTIALITY springs to mind if ever a request was to be made.

Sorry to be pessimistic but the invoice will be for the contracted hours, not the actual hours spent. If you can find a care agency who go through timesheets and invoice for “time spent” it will be a first.

A lesson I learnt the hard way when Mum first paid for her care. She received four 30 minute visits a day, as I was present the average call lasted five minutes because I was doing everything for Mum. They charged £20 an hour.

So effectively Mum was paying £40 a day for a total of 20 minutes worth of visits, at which point I got rid, for any mathematicians out there it works out at £120 an hour Mum was paying the agency.