Help Your Claim Ltd...advice

Hello folks. I was recently cold called by Help Your Claim Ltd with reference to an Abbey PPI policy i had which secured my old mortgage with them. FYI the borrowing was repaid and the policy cancelled circa 2 1/2 years ago.

Where i'm slightly uneasy about making a claim is that, due to an issue with my employer, I sought the policy from the abbey approx 2-3 years in to the life of the mortgage, they did not 'sell' it to me.

I have stressed this point to HYC but they are adamant i can make a claim. They are also looking to charge a 30% + VAT fee on a 'no win, no fee' basis but have advised the interest on my payments that they will also claim will cover this comfortably.

My questions are these...

A) Does anyone have experience of this company and are they reliable/reputable?

and

As I went into the policy knowingly does that void any claim I may have.

Thanks for any help/advice.