Trade Fair, debit for dividend on FTSE rolling

Trying out the demo and confused about this, was debited for dividend on 20/04/2010 for the FTSE rolling daily, then got charged again at 19/05/2010 (much bigger amount due to the increased trade). Really confused about how this works, got charged £520 initially and now £75,000? New to this would appreciate it if somebody explained a little. Thanks.

I noticed in the email is said for one of 7 of the £10,300 debits was for

Dividend transaction for trade (7567331) Sell 200.00 of FTSE Rolling Daily.  Debit: 10300.00 GBP