FNB HOSPITAL PLAN PROBLEM

I have problem with FNB HOSPITAL PLAN,they promised to pay you money for the day you spend in hospital but when is time to pay ,the problem start .I was hospitalized for 5 day but they only paid for 4 days and I asked why ,I was looking for the explanation of why they didn't pay for the 5th day, no one responded, even the hospital statement shows 5 days of being hospitalised. FNB PLEASE ,explain why not paying all days I spent in hospital .how you calculate days cz Sanlam paid for 5 days as ghe bill stated