Settlement amount on loan account

I contacted company on 17 Feb for a settlement amount and received a letter with settlement amount R3625. I however requested amount f I r 25th and that value was only valid till 22 Feb. I subsequently sent 3 more emails requesting settlement amount for 25th Feb. I received a settlement letter today with an amount of R29k. I find it difficult to understand how 3 days can have that big a difference if settlement amount. I tried phoning them but the call was cut, not sure what happened. I also requested a break down of the settlement amount as I'd like to understand how the got to both amounts.