Respite Drama

So 5 hours after I dropped R1 off back with his foster family, the foster mother is calling me to come back and pick him up.  She "made a mistake taking him back" and wants me to keep him for a few weeks.  At the beginning of the respite I gave her the benefit of the doubt due to the family circumstances that were bringing him into respite in the first place. However, as the week went on things just seemed more and more off with our conversations.  On Saturday she asked if I would be able to keep him the following weekend as well if his therapist didn't want him attending the family function that was being scheduled.  I said I would.  They were supposed to pick him up Sunday evening, she told me "He wants to stay till Monday so Ill just pick him up then".....um asking ME if that was okay might be nice.  When Monday comes she tells me she is going to need me to transport him to her since her husband doesn't drive...although she was there when we dropped him off and she drives, so.....?  When I drop him off she tells him he is coming with me next weekend, which means she didn't really check with his counselor on how to handle this situation, in fact no one had explained to him what the situation even was.  So she goes on to ask me when I can pick him up on Friday.  I ask about his school dismissal time and tell her I can pick him up around 5 after my son gets home on the bus.  She tells me she doesn't need to send him to school and I can come pick him up around 12 from her house.  No, not going to work lady!  Anyway I say I can pick him up directly from school on Friday and bring him home Sunday evening.  I left already feeling like she was taking advantage of me and the situation.  Less than 5 hours later she was calling for me to come get him.  I told her no, there is no way I can get him to and from his school everyday, or the 45 minutes each way to visit and counseling.  On top of that he has a safety plan that I wasn't informed about originally that is really hard for me to follow as a single parent.  I mean line of sight supervision is kinda hard when the only adult in the house would like to take a shower or pee!  I'm really frustrated and feel bad for R1, cant wait to see what happens tomorrow....wonder how long it will take the agency to call me and try and convince me to take him all week?  I don't want to sound cold or heartless to this foster families situation but I went into this round of fostering telling myself I was going to stand up for myself and what I want this time around, not get walked over, and here I am first situation in and already feeling taken advantage of, ugh.