Hen do issues :-(

So I thought I'd got my hen do all sorted. Having listened to my bridesmaids unspportive reponse to what I wanted to do I changed to a theme park one day and an activity on the next as this was what everyone seemed to want. I sent out invites and got yes's/no's back, fine so I thought. I sent further info re cost etc and still everything was fine. I asked finally to make sure and told everyone that I had to pay when I booked, most asked for my bank detials there and then so I still thought everything was fine. Its now 1 week to go and I've had 4 drop out ☹️I thought this might happen so booked allowing for 2 to drop out but not 4! If I cancel, I lose all my money, if anymore drop out I'll have to speak to the centre as there's a minimum number on the activity. I'm so upset! the activity was £30!, I'm providing the accomodation and food the night before, it's not exactly an expensive weekend!. One has said that she can't afford it as she's had her car break down and has just booked her holidays (and shes my tog too, so can't afford to upset her) and the other has said she's not well enough (but well enough to still compete her horse!) neither have offered to pay and because the £30 was based on 8, and the others have paid, I'm out of pocket £60. One of the girls who cancelled early on offered to pay, but I counted her as one of my "drop outs" I told her I'd allowed for 2 and not to worry about it. Sorry this is a bit more like a rant but I'm so upset they left it so late to tell me, left me with the bill and have nearly ruined my hen before it's even started! They are both day guests with partners and when I think of what I've spent on them and the consideration I've gone to for my guests and they can't even afford me a little thought!!! Arhhh!