No assistance from Out

I have submitted a third party claim with Outsurance. 8 calls later. 4 emails with all the relevant documents sent and I am told that the documents are not attached. I understand that your client is your priority but why is there a legal department for 3rd party claims if no one wants to assist. I'm told that it's my responsibility to follow up but what else should I do if no one is responding. For such a well recognized company the service is really pathetic to say the least.