Changing DWP mailing address, temporarily

Hi guys. Mum is sick, I have to stay in her (a different) town. ESA sent medical questionnaire form, on 29th Jan, to normal address, they say. Asked them to send to mum's address, they refused. They will only send to a "new" address, if I say I live there. But I happen to know (luckily for me, so I don't make this mistake), that if I tell them I have a new address, then my housing & council tax benefit is cancelled, & ESA & pip benefits suspended. (Change of circumstances). The guy on phone sounded disappointed, that I didn't fall for his jobsworth trap, & mess up my finances, risk eviction etc. But anyways, back to the point.. I asked dwp if I can download the ESA form online, or pick one up from a local jobcentre, because it's hard to get to my normal address right now, and they say no. Plus, they won't give me extra time to fill it out. But, they put note on system, so they say that, they won't stop my benefits, if ESA form is returned "late". So,,,, I finally spend money I can't afford, (and time I can't spare) (also stressing my sick mum), to travel far, purely to collect the ESA form, from normal address, &.... ESA form isn't here. I guess I can call them again & ask to speak to a manager? And say I need esa form sending to a temp. Mailing address? Or that i need to be able to collect a form locally, or download one? But in the past, escalating problems to managers hasn't helped. As we all know, dwp do not gaf. So, do you have any ideas? Esa Form might have been stolen, because a package was also stolen. This is what happens if not at home to keep an eye on mail.
Thanks jenbo.