Random reviews by DWP

After going through the ordeal of an assessment for PIPs, i was awarded enhanced care and mobility, not to be reviewed for five years. Imagine my shock when only four months later I was called in again for another 2 hour home review by the Performance Management team. I was told that my name was picked at random. I had no idea DWP did this. I think this is disgraceful to put a seriously ill person through two reviews in four months after sending a letter saying they would not be reviewed for five years. I was told that there was no guarantee that I would not be pulled out for another random review at some time in the future.