This may be complicated so I apologise if it doesn't make sense.
So Ds 2 has just started secondary. The school is local but still a car journey away, I work 3 days a week and also have Ds 3 to get to primary school and dd to nursery. It's hectic and involves a lot of back and forth journeys, getting stuck in traffic and me nearly always arriving a few minutes late to work.
There is one other boy going to this school who lives in our area and Ds 2 is good friends with him. I approached this boys mum about a school run. I asked if she could do 3 days and I do 2. As I thought this felt slightly unfair to her I offered to also take her younger son to his school so she had no school run to do for 2 days.
Last week went fine. This week, the older boys have wanted to start after school clubs. There was football today and it was my turn to do the run so I spoke to the mum this morning and said obviously I would be picking the older boys up at 4.30 but when the timings are different it would be difficult to pick her younger son up at 3.15 from his school. This would mean 2 separate trips in the afternoon. She said she was working. She had not considered the fact that her younger Ds finished a lot earlier. So I said if it was difficult today I would help but she said no she would do it.
I can be a bit rubbish at saying no to things like this normally and was trying hard to be fair but assertive. I would not dream of asking her to go out of her way to collect my little ones so I felt quite strongly that going out of my way to collect her younger son at a much earlier time was unreasonable.
I worried all morning that I had let her down so texted her lunchtime to remind her that if she was struggling I would help out today.
Heard nothing until 4.20pm as I am loading the little ones up to go and collect the older boys. She sent me a text saying she had had to leave work early to get her younger son and ' it's great to have friends, isn't it?'.
I saw and replied to this text outside the secondary school, waiting for the older boys. I told her I thought she was being a bit unfair and she had assumed that I would always go out twice to collect all the boys when after school clubs occur. She clearly thinks I am being unfair. Pointless texting back and forth starts up. And I admit to feeling I had to fight my corner as her text messages were unbelievably patronising and passive aggressive.
After 20 mins of waiting for the boys, I went to check if they were still in school ( my Ds is known for chatting away with his mates in the changing rooms!) But they had left already. I drove around looking for another 15 mins then called this mum. She didn't answer my calls or text messages. Then I tried her home phone and her older Ds answered 
. She had gone and picked them up herself and hadn't bothered to tell me. By this time I was on the verge of tears and furious. I drove home and only then did she text me saying she had picked them up, my Ds was now home and she would speak to me when I had calmed down. 
I have told her to leave the school run. It will be tricky but I will manage on my own anyway. Just seems a shame when we were both benefiting. But I don't like confrontation and it has left me feeling awful and doubting myself. Was I unreasonable? I hate to take the piss out of people and consciously tried not to do this with this mum. But apparently I can now go and 'find some other mug'
If you are still with me, you deserve a medal. And please don't flame me. It's a sign of my upset state of mind that I am even brave enough to post this - she knows I like MN and if she reads this, it will be pretty bloody obvious!