Disability premium stopped no notification

Help i would really aporeciate a speedy response. Basically my payment stopped today reduced for employment support allowance. I am awarded a pip claim till 2019. But today esa stopped my severe disability allowance on my premium which i get topped up on the esa. Im in support group. My review date is coming up and sent the forms off correctly. I had loads of evidence from my dr at the hospital that my condition has not changed. That i still have difficultys walking a functional report. My question is are they allowed to do this! Just stop it no letter as yet explaining why. I spoke to a esa advisor on phone. He said there not supposed to just stop the allowance without discussing it with me first. Can you advise what i should do please can one of the advisors on here reply as its quite urgent. Im really stressed worried. The only thing i can think of is someone has rang in or watching me there dwp spies. Im really careful as i dont break any rules. And i can hardly walk let aloe get around thats whyi got mobility for my M.E.cfs and hypothyroidism. Please help me any info appreciate what i should do my next steps to get this sorted out reinstated.