DWP text please help

I’ve received a text today from DWP saying they want to look at my esa claim again. This was only done last year and everything was fine. Are DWP open on a Sunday or is this a spoof text? I’ve tried ringing the number on the text but it says it’s unavailable. Google says DWP are open 7 days a week 8-6 but I’ve tried to phone and can’t get through. Please can someone advise me. I’ve got severe mental health problems and this has sent my panic attacks through the roof

I also received a text message today, saying 'we recently sent you a letter to say we need to look again at your ESA claim' and that they would ring today. However, I have not received a DWP letter saying this. The number given to call back, when you ring, leaves a recorded message for Pinnacle Insolvency. I had an ESA medical very recently and received the decision letter in January 2019. This is a bit strange, and reading this, I'm not the only one who has received a text message.