Leaser woes...

When I bought my horse, it was not my plan to lease him out. But while at the first barn I boarded at, I took a little girl who was leasing another horse under my wing. She reminded me of myself when I was her age, and being rather timid she was pushed around by some of the other schooling kids. Turned out, the lady who owned the barn was a whacko (a good story for another post) and sold the horse that this little girl was leasing without saying anything! She never brought it up, no money was refunded, it was awful. This little girl just showed up one day and her horse was gone. She was devastated! I felt bad, so I asked her if she would like to ride my horse when I was out of town.

When I switched barns, I couldn't bare to take another horse from her knowing how it would have made me feel when I was her age. So I offered to let her lease my horse and ride him 2x's a week. Lately, my leaser and her mother have developed a habit of calling to cancel their day, and then want a make-up ride. When it started to get out of control, I raised my rate to make up for the extra days they were getting. Then they just started showing up whenever! So I told the mother they can't just show up on saturdays, they get 2 days during the week. But they keep canceling and wanting make up rides and I'm not getting to ride my own horse sometimes! If I make other plans one day because I think they are going to ride, that's a day I lose. I don't need the money, that's not why I lease. I want to drop them but then I remember that theres a little girl involved. How can I get them to come on their days? When the mom would call and ask for a make-up day, I told them what day I could offer and no more. But she figured that out real quick and started having the little girl call because she knows I can't tell a 12 year old no!!!

Sorry so long!! Just wanted to give some back story. Any advice would be great!