BA Baggage Delay 8 Days, Domestic One hour flight!!!!!!!!!!

Just before Christmas i took a Domestic One hour flight from Heathrow T5, when the Plane arrived 40 passengers luggage did Not.
BA Flew it up the next day, they hired Rico courier firm to Deliver it to the passengers, 4 days later Christmas eve my Bag has still Not been Delivered.
My insurance firm say go and spend up to £200 on essentials, i spend £166 but i incur the £50 excess fee.
I Ask BA to pay this £50 because of their`s and Rico`s incompetence, i recieved my bag after 8 Days!!!!!!!!!
Last night BA reply;

While I appreciate your reasons for asking, I'm afraid I cannot reimburse the Excess charges that you had to pay to your Insurance Company. I would, though, be glad to contribute towards the essentials that you had bought for the time you were left without your luggage.

I must also add that airlines have only limited liability when it comes to compensation for missing or damaged luggage, so it is standard practice for passengers to claim directly on their travel insurance policy. It speeds the claim along and avoids you having to deal with two companies at once.
I know that this delay with your luggage isnt what you expect from us. Thank you for letting us know about it and I hope my email assures you that this area is a high priority for us.