Can my insurance ask for anything they want and I have to comply.

If you want them to process your claim, you have to comply or you have to sue them (see below). An insurer may investigate claims, and not infrequently does when theft is involved if no suspect is caught or at least identified: in those cases, there is a not-unreasonable possibility that the claim is fraudulent in some way (e.g. homeowner never had the allegedly stolen items; homeowner hid or sold their items while putting in a claim; etc.). Bank records and cell phone records are relevant to such an investigation, since the bank records can shed light on your finances (did you have a motive for insurance fraud? is there some unexplained transfer of money that could be part of a criminal act?) while phone records can show who you were contacting (e.g. a known criminal or fence, to possibly arrange for the sale of items supposedly stolen). So these are not unreasonable things for them to ask for. If you don't provide them, they will almost certainly not move forward with your claim.
They can't deny a claim without you having the right to a trial on the subject. You can file a "breach of contract" lawsuit vs. the insurer, on the grounds that they were contractually obligated (an insurance policy is a contract) to pay this claim. But in the lawsuit, you will have to prove they should have paid, and they get the chance to disprove it--such as by showing that there is reason to think this was insurance fraud of one kind or another. Because in a lawsuit, each party can get information or documentation from the other side using the legal processes or mechanisms of "discovery," like compulsory document requests, you'd very likely have to produce this information anyway if you were to sue your insurer--you may as well produce it now. You can get duplicates of phone records and bank statements from your carrier and bank, respectively; you should request and provide them.