@LizB62A
They could have just got muddled up. I was having my weight monitored, and was (for example) 12 stone 5 pounds, on 3rd May 2018.
Then I went to get weighed 2 weeks later on 17th May, and was 12 stone 2 pounds.
For some reason, the nurse who weighed me, logged it as 11 stone 2 pounds! 
I didn't realise this til 7th June (3 weeks later.) I went to get weighed, and the nurse said 'hmmm, you have gained weight in the last 3 weeks.' I said 'eh?! But I have been so careful and good!' She said, 'maybe, but you have still gained over half a stone. You are 11 stone 10 pounds!'
I said 'but I was 12 stone 2 pounds three weeks back, so I have actually LOST 6 pounds.' She said 'no, you were 11 stone 2 pounds 3 weeks ago, so you have gained 8 pounds.'
After a bit of debating, and pointing out that I could not have gone from 12 stone 5 pounds, to 11 stone 2 pounds in 2 weeks (3rd to 17th of May,) she finally accepted that 12 stone 2 pounds was recorded incorrectly as 11 stone 2 pounds 3 weeks earlier!!! And she corrected the record!)
So yep, it is not impossible for them to record stuff incorrectly.
A scam though? I doubt it...