If you looked at the data from a neutral perspective, were there patterns visible and deviations from them that could have caused suspicion?In my case, I have a paper ticket. GAs second correspondence to me was to send me a spreadsheet of all DR claims for the past 18 months. They do not have any smart card tap in data to use as evidence against me so I find the whole process extremely suspicious.
I'm not for one moment suggesting GA have acted proportionately or in a reasonable timeframe. But there are suggestions on here that they're adopting a carpet-bombing approach in bullying anybody who's claimed DR in the last 2 years when from what I've seen most of the challenges have had some substance to them. A number, even a majority, of posters have admitted that at least some claims were not valid. It's inevitable that if you're reviewing so much raw data (and I imagine GA have got rather a lot of DR claims to use as a dataset) to identify patterns that you will find some people with patterns that are initially suspicious but do have entirely legitimate explanations. GA are also acting badly in requesting repayment of all payments when only some appear to be questionable.
I don't think GA should be challenging payments after this length of time, nor do I think they should using the hostile approach indicated by previous posters. However I don't think the process of reviewing claim data to identify suspicious patterns is intrinsically wrong. It's just that they should be doing that before they make a payment.