esa and severe disability premium

Hi i receive severe disability premium with esa as i get PIP i never applied for this and was automatically given to me in 2016. My PIP was stopped in march 2018 and reinstated in July 2018. I have continued to get SDP from July but it has not been backdated to March. When i phoned up ESA they said it has been referred to the compliance department and that there is nothing i can do about it as they have no numbers for them and she had no idea how long it would take. I am relying on this back pay to pay bills and was told 3 weeks ago i would receive it in a few days, to then be told it could be 6 to 8 weeks to then be told they have no idea how long it will be. She also said i may not be entitled to it as i don't live alone, which has confused me as i have always been honest and told them i just rent a room from my Landlady other than paying her rent from housing benefit and other bills i need to pay her my money is nothing to do with her, she doesn't claim carers allowance for me. So why are they questioning it just for the period of march 2018 to July 2018 when she is classed as not being part of my household and they are happy to pay it now, it doesn't make sense. I'm really worried now and have got myself in a bit of a state over it and wondered if you can shed some light on this and who i contact to get help. Thanks so much for any help you can give.

Thank you so much Gordon i got myself in a right state...it was the way the women spoke to me over the phone she acted like i was being investigated for fraud and that i had done something wrong..which confused me as i was getting payments now, and absolutely nothing has changed for me over the past few years, but now i understand that the payments are treated differently and are checked differently it makes sense. Thanks to you my weekend wont be so bad after all