Terrible claims experience

Very easy to debit your account very hard to make payment when something goes wrong I have been an old Alexander forbes policy which was taken over by Momentum really didn't want to move from my previous insurance but apparently Momentum bought them outright anyway long story short I had a break in on the 23rd December the took a whole lot of stuff was confirmed by police they did there own investigation. The ********s also took my small safe at home where I keep all my documents and receipts for items .now I have been paying for 6 years on a specified laptop that came from my previous insurance to Momentum now at claims stage ask me for proof of this item when it was already on there system with serial numbers how can I prove existence now if my records and item was ****** very dissatisfied with the claims experience