Agree with a lot of what catsmother has said. Only thing is though, at 15 your DP is not necessarily taking you for granted or expecting you to "look after" her during the day. Because if you weren't around she could presumably look after herself for the day and your DP could sort her out dinner, etc when he gets in. That may be how he's thinking.
I end up in a similar position with my DSC sometimes as DP agrees to have them for chunks of the holidays, often months in advance, then ends up taking on work commitments. For the younger two, I really don't mind as they play happily with my own DCs and I'm comfortable with parenting them. For the older two, (aged 14 and 15) however I find it much harder, something that I often have to spell out for DP. One thing that helps is if I talk to DP in advance and make him agree with the DSC what they are supposed to be doing all day. Eg what hours they're allowed to game on computers, what time to be in by, etc. I'm then left to enforce rules that we have set and he has already laid out for them - which is a much more comfortable situation to be in as a stepparent than being the one who tries to tell a DSC what they are and aren't allowed to do.
What would you like DSD to be doing during the day? Could you, say, spell out that you'd like her to cook one meal a day, be up by 10am, or whatever you think she should be doing? Could you ask that she has a quick chat with you over breakfast each day about her plans for they day? What actual things would make it better?
I think you're entirely justified in the way you feel, and right to talk to DP about the difficulties and ask him to help make things easier. For both of you possibly, as DSD may be behaving as she does as she's not very comfortable around you either. If he could get her to identify why this is and how it could be easier for her, that might help too.
I don't think it would be reasonable to actually ask him not to have her stay though, or demand that he takes the time off work, as she is old enough to take care of herself in the day if needs be. So it's quite a different situation from him asking you to care for her. Annual leave never goes as far as you want it to, and her mum's entitled to a holiday from time to time too.
If that all fails, then make plans of your own for the times when she's around - do stuff round the house in the mornings whilst she sleeps, then take yourself out for the afternoon. If she leaves the house in a mess, get your DP to pull her up on it when he gets back in the evening.