'invitation' to a work focus interview

I sent a letter asking have they transferred me to ESA without following their published timetable of stages. Got letters and my husband rang them to check and both letters said part of IB review process. Following day wham there is the offical letter they are going to assess me for ESA. So the process has begun.
I am very stressed. I know I should be in support group according to the criteria but I dont trust that this will happen. I am in process of getting supporting evidence from health care professionals.
I was going to send a letter askign if i stilll need to attend for the WFI which is in a few weeks time. Do I really have to go to this when they are just starting process and I am waiting for the phone call as the form says will come next. Or as they already have me booked for WFI will they jsut use that to do what the phone call would have done. It seems so unfair to ask me to attend when I have told them I cant use public transport. It is just so wrong!

a similar thing happened to me although mine was regarding esa. i received my es50 to fill out, which i did and sent back to them. i was then waiting to get called for a medical, instead a few weeks later i received a letter saying i,d been placed in the wrag group and would be going on wfi's. i couldnt believe it. i hadnt even been seen by anyone. next i receive an appointment to go pathways courses. i rang the lady up and told her i hadnt had a medical or been seen by anyone and they've placed me in the wrag and to come and see her for these interviews. i explained to her how ill i was and that i cant even get out the house to see her. she told me to appeal immediately and as you cant cancel these courses she deferred it for 3 months to see if i,d hear from them meanwhile.she also told me to get the medical report/evidence from them to show their reason for placing me in the wrag. i did this. within 2 months i rang the dwp to see why they credited my account with a small sum of money and they told me i,d put in for an appeal but to cancel it as the money was backdated as they,d put me in the support group. i must have rung them every day for a week to clarify this as couldnt believe it, till this day i havent received a letter from them but each time i rang everyone said the same thing, you,re in the support group', and obviously my money went up. again, all this with no medical nor seen by anyone.