Royal ripoff

All goes well until you need to claim. They don't let you know of so called preferred service providers so in my situation where my entire back windscreen was shattered and I went to the closest glass fitment centre to have it replaced and paid for it up front and then sent through a claim I was told they only use 1 glass fitment company with a ceiling cost of x amount so they will only cover that amount less the excess. This was after me calling and emailing for a week to get an answer. I was away in a small town with 1 glass fitment centre at the time of the incident so I asked if they felt it was ok for a lady on her own to drive 2 hours to their preferred service provider with no back windscreen to which I was told they only use that company so clearly they do think it's OK. Well I am down a fair amount because I won't sign their disclaimer out of principle to get out a fourth of what I paid and so I don't get penalised for their ridiculous policy but they will be down a whole lot more as I will be removing 2 vehicles from their insurance portfolio and a family member will be removing his and going elsewhere.