Kinda666,
sounds like your company may be using an external finance company to fund the scheme. This is common among companies who aren't that cash rich (or scared of the potential take up among employees for the scheme, as at the end of end of the day they have to initially fund it)but want to run the scheme. Therefore the savings aren't as great as they pass on the cost of borrowing the money to you.
sorta sucks, and your savings won't be as great, but you'll still make the savings compared to a normal purchase, and it's spread over an amount of time. Seems correct to me.
mail in profile if you have any more questions.
hope that helps.