firstly you need to claim estopple which advises them that they paid something which you beleived rightly that you were entitled to and so therefore have no possible means of paying back now it's been spent.
They have no case if they have made you redundant and forced all people to be tupe'd accross then they have to make good all payments and services up until the date of transfer. Your employment would cease with them on the previous day, or as specified in the redundancy notices. Unless you specifically say this is my last day then your contract woudl ahev been terminated along with everyone elses on the final day before the tupe was enacted.
even if you did end you contract early then you would be entitled to the percentage worked of any renumeration previously earned ie if the this was a whole of year bonus you would be entitled to it all less the day not worked on a percentage/pro rata basis (ie you might say owe them a few quid not the whole amount). speak to your HR department first claim estopple then see a solicitor, don't forget if they are wrong, and they are, then they will have to pay your solicitors costs.
A strongly worded letter advising that you beleive there is no case and will be seeking costs and compensation shoudl this matter go to court plus intrest on any payments with held or retained at (pick an average of the high street intrest rates 5.6%) for each day the money is illegally with held...
This will put the wind up them, and should reslut in them being more reasonable if not dropping it all together, if it doens't then make good on your threat and take em to court. remember they might have to take it to court if some one has paid theirs back although their circumstances will be different from yours so their action may have been totally correct where as it might be totally wrong in your case.
Seek professional advise either way.
