Liberty unfairly delaying claims process

I submitted a valid claim on 04/05/18. The standard claim assessment period is 5-10 business days. I did a courtesy follow up today & was advised that they need a further 10 business days. No further information or documentation is required - just more time. Liberty yet again purposely delaying claims processing. This is unfair to me as a claimant, that has already jumped through all Liberty’s to submit a full comprehensive claim pack. I want the matter fast tracked.