Harringtons Advisory???

My mother was taken into hospital last week with a stroke and will not be out for a while. Now I remember a while back, probably about 6 months ago when I was still living at home that she told me solicitors acting on behalf of Natwest had contacted her about her about them miselling her PPI. I asked at the time whether they really were Natwest and she said yes. She is 68. I asked because I know I have had PPI calls at work and on my personal mobile which unless you ask the right questions, try their luck and cleverly word their conversation so I think mum was fished in by them and really believed they were Natwest/RBS solicitors and all she had to do was sign the paperwork she was sent by them. Had I known the true situation at the time I would have claimed for her directly with Natwest, but she didn't. Now she is in hospital, my sister and I are trying to arrange her bills to be paid (and of course, she is of the generation which don't pay ANYTHING by direct debit, causing a bit of a headache as I can pay the RBS cheques in but need to wait until LPA until I can pay money out on her behalf. However, I have discovered Harringtons Advisory paperwork which indicates that they want 39% of what they "won" for her! Within 10 days! Even if I pay the RBS cheques in and they clear, I can't write any cheques out on her behalf and to be honest, I know it would be difficult to argue whether she realised what she was signing, I do have a vague plan that I should do the following:
1) Phone them and back up in a letter of her current situation i.e. she can't pay within their timescales.
2) Ask them to stop further interest payments due to the delay
3) Ask for a copy of any signed paperwork that she submitted to them (or inform them of my intent to rerequest once my sister and I have LPA)
4) Ask for a copy of the transcript of the phone calls they have made (which I realise they will be able to charge?)
I am disgusted that they would target an elderly lady with a cold call resulting in this and skimming over the truth that they are trying pot luck that she will say that she has had a loan with them. How do they find that out anyway? And we changed from Talktalk to BT because of the amount of sales calls she was getting and she is ex directory - how the hell did they get her number? CAn I legally ask them where they got it from? (Once my sister and I have LPA). My mum needs this money to cover her basic bills for at least the next six months and all us kids are chipping in, but to be honest, I think the amount they are expecting is absolutely unreasonable. Can I ask to have copies of all the documentation that they submitted in respect of the claim via an Information Directorate request (again, once have LPA?). Any advice gratefully received because this money will go towards getting whatever care she needs so that she can get home as soon as possible and not have to worry about no income for a couple of months.

I signed up with this Company in Nov 2014 - I was fully aware of the fee they charged but I don't recall them mentioning that I would have to pay VAT too, though I suspect this is the case, although it is now Jan 2015 and I have had to chase them up to find out if there is anything owed to me. In the initial call it was 'suggested' that I 'might' get something back prior to Christmas 2014 (the main reason I agreed to undertake the process was that I have a young child and am currently in a financial slump) I suspect this was their 'party line' in the run up to Christmas, even though they were well aware that the backlog for claims was clearly running into more than the 8 weeks time limit given to the banks, and that they used this line to hook people in. In my case, the PPI is owed from a long time ago, this apparently means that my details will have been archived, making the process take even longer than usual and they say have no idea what sort of timescale is applied in this instance.
In short, I've been waiting 3 months now and they still can't tell me how much (if anything) I can expect to receive (and keep) or when I will get it. Watch this space...