how long is too long for a settlement to complete?

my insurance claim for my stolen car is now edging over thirty two weeks long. initially my insurers offered a settlement within twelve days of my claim which was five hundred less than what i valued my car at, close enough i thought not to contest, so i accepted this in writing... three days later my car was recovered by the police seventy miles away in another city, so i informed the insurers of this and after countless letters answering seemingly the same questions with the same facts, a missed mornings earnings due to hosting an external assessors interview and it appears my claim has been shelved, further phone enquires to my handler have informed myself that enquires are ongoing and that they are still waiting for the police to confirm their requests... so my question is how long is too long 'cos i am feeling close to the threshold presently and what options are there available to hurry them up to settle?