Electric wheelchair what do I do

Last year my GP referred me to NHS wheelchair services as I struggle to walk any further than20, due to severe constant pain and fatigue. Instead of sending me to be assessed they rang me and said I had to buy my own...I said what with as I am on disability benefits. At time I was on standard PIP for  both bits. Aftet I kicked off cos I am stuck in home due to this, she said she would speak to someone and get back to me. Still waiting several months later no calls or lettets. Since then PIP reviewed now on enhanced rate for both. Now cos I live in a very steep area, with uneven surfaces and I am classed as "bariatric" and the street at both sides of my house is a 20-25° hill I can only find one wheelchair suitable and it will cost in excess of £20,000. I have test drove several electric wheelchairs on both streets my house is on and they either don't move at all or tip up. So what do I do to get the wheelchair I need to get out of the house to see my friends, go to mefical appointments, socialise. Hell to get put of hoyse and go on a bus or a train anywhere but these 4 walls? Will NHS provide it. If not how can I get it as I have no savings left, with various benefit changes coming in and mortgage intetest rates going up the extra PIP money will no doubt have to be spent on paying coubcil tax and the shortfall between the SMI loan and my mortgage ....so what do?????I need to get this wheelchair. I need to get out of this house Im only 45. I don't even know how Im going to pay for my gas use over winter yet ad I have had to have it on for 16-20 hours a day since October cos I am cold. Any advice or help will be appreciated.