bedroom tax exemption unabled to share bedroom due to disabilities

Hi new member here any advice  reguarding law change 2017 by goverment to disabled couple  unable to share bedroom due to disabilities.

We live in housing association 2 bedroom bungalow with full wet room ,

Way back on numerous occasions  since  2018  been ringing my local council housing benefits office told point blank no exemptions to bedroom tax  as unable to share bedroom due to disabilities.

Only till  this year came across a post stating that law was changed in 2017.

I have  been   into council with ot accesment  which states all my disabilities etc   and medical condition   explaing due to severe spinal problems I have to sleep on side on a couch.unable to share a bedroom with my wife , who also disabled.

Council  wrote me a letter the other week stating no law such existed for bedroom tax exemption due to being unable to share bedroom or bed.

Then next paragraph said you stated due to your disability you stated you slept on couch need more information,  ie where  is the couch in your lounge spare bedroom .please send details we look into iff we can help you.

Surely  council are contracting  them shelfs staing no such law exists.

Anyone one please advise on actual wording off goverment law change in 2017

I beleive council are putting ther own spin saying no such law exists. Surly this is incorrect .  any input help  much appreciated   mike in north yorkshire