Battle to get claim paid

I submitted 2 Gap cover claims. 1 was paid & the other 1 has been dragging on for months. Initially I was told it was an oversight & 1 had been accidentally missed as 2 were submitted at the same time. Every time I phone to follow up I get told it will be referred to an underwriter to contact me but they do not take phone calls so I cannot speak to the person. Mails I sent were not answered for weeks and then they asked again for documents I had already sent. Today I phoned again & was told I'd receive an email reply within the next hour or 2. Needless to say, no email.