Overtime and Holiday Pay Due

Annac0512

Hi,
Me and my colleagues have all been made redundant and are fighting to get extra hours worked and annual leave paid.
We all have weekly hour contracts but is classed as flexi-time as we could work more or less hours each week.  Before lockdown a few of us had extra hours but are now fighting to get all these hours paid.   We were unable to come into work during lockdown but were never given a clean cut answer as to what we should be doing during this period.  To begin with we could work, then told to go home, then we could go back in, then told to go home.  Some but not all were redeployed to other departments.  When agreeing to be redeployed they then didn't have the equipment available for them to do the job.  This meant quite a few people were sat at home doing nothing but still being paid.  For those who had extra hours are now being told these hours need to be used to compensate for the hours they didn't work during lockdown but were still being paid.  We have said that we were told different things throughout this period as to what we should be doing.  Also those that didn't have any extra hours or even owed hours who also didn't work have still been paid but are not being asked to owe pay.  We now have to prove what work we did during lockdown and how many hours this equated to in order for us to be paid all of them even those these hours were earned before lockdown.  
We are also having trouble trying to get all the holiday pay which had been carried over from the previous years entitlement. 
Are they right to refuse paying the extra hours and holiday pay?
Thanks