Considering many insurance companies do either end up rejecting motor insurance claims or reduce the payments they make, here is an article explaining how to deal with exactly that scenario.
Several factors could trigger such an outcome. First of, your insurer might come to the realization that you were the main culprit in the accident you put forward, if it is a claim related to theft from the car, or maybe even the car itself.
It could be found that your car insurance policy has a clause written in it which would invalidate any claim, or it could be decided that the claim should be settled under another policy such as your home contents insurance (particularly in the case of theft from the vehicle.)Providing any information that is inaccurate or a lie can also lead to the rejection of your claim, as well as being unable to provide receipts as a proof to claim for thefts of the items that may have been in your car.
Lastly, if the book price of the car is a lot less than the money you have invested in it, you may lose out to quite a high degree. If you undertake an insurance policy, your insurer will fully expect you to give up any details that could be of help or importance to them, you should be doing this even if you are not asked to. Many insurance companies have been known to use this easily grey area perspective on the sharing of information to give justification for their rejection or downscaling of claims.
In addition, best thing to do is to remember that the small print of your policy carries a lot of weight so to stay safe, study it thoroughly before, during and after your claim. Keeping accurate records of conversations and correspondence as well as any receipts, can be a huge help in backing up your claim.
Then, if it appears that you still feel something dodgy is afoot, your next step can be to contact the Financial Ombudsman Service, (FOS), who gives resolution for conflicts between insurance companies and customers. To do this you must first confirm your insurance company has dealt with your car insurance claim in full. You can raise your complaint with the FOS once your insurer gives a letter or final response to your complaint or has failed to do so within eight weeks.