Data matching mistake??

Hi everyone, I received a letter on thurs 15th of March from the DWP saying they are reviewing my benefits and circumstances and I need to attend an interview on the 26 th. The letter heading said local service compliance. I had one of these before about 6 years ago where I went to the interview and basically my lovely ex had made a malicious call to them accusing me of benefit fraud, this was nonsense and was thrown 8n the bin ( actuallly by the officer in front of me).
Well with this new letter arriving I thought oh here we go again but I decided I couldn’t wait to find out what it was this time. I gave them a call and to my surprise it wasn’t a malicious call ...they asked me if I had £48000 in savings in my natwest account and a morgage! Apparently my name had been flagged up by the data matching system. I live in a small rented flat and I am way into my overdraft with zero savings or owned property. I told him this on the phone and he said it’s probably a glitch in the system! He then asked if it would be ok to conduct the interview over the phone, which I agreed to. I was asked again if I had this money again or any monies amounting to more than £6000 and whether I owned property. He then said he’s happy with the interview and my answers and said that will be the end of it. After looking at the letter it does say I need to bring an up to date bank statement, pension provider, individual savings accounts,income;premium: or capital bonds and details of land and property I own!

I could of been stressed for nearly 2 weeks waiting for this interview, I’m just glad I called. Has anyone else heard of this data matching system having these kind of problems?

What info can be gathered by data matching?