need some legal advice

when i got my phone and insured it i was told its insured from the day i leave the shop with it

now im been told its not insured as the sim wasnt activated

can anyone give me someadvice?

I'm not sure there is much you can do unless you can get some proof that you had/have insurance on it. This information is usually on your bill, or even possibly on your original receipt. If you no longer have your receipt, I believe many businesses are able to get a copy of it, but it may take a while.
Was your phone stolen? If so, (I'm sure you know this) keep calling it periodically and perhaps someone will answer it. Also if it had GPS in it like most phones do now, you might be able to have the company, or even the police locate it for you.

Not sure if this information will help you at all, but I thought I would try.

its a N95 and has GPS
also it was lost and insured aswell (the company claim it wasnt insured as the number wasnt transferd at the time)

i am writing a formal letter