PI cant understand her at all!

Okay, this is a really long story. I uploaded the conversations on instagram as well.

This matter had dragged from 2012 till 2013. During the year 2012, somewhere in mid october before my exams had started, i need a spare phone urgently. My phone had spoilt and need to contact my customers urgently so I went to a certain facebook group and see her advertising her phone. I fb msg her regarding the phone and arranged meet-up on a saturday. I realised I couldnt make it due to schedule crashing, i pm-ed her right away when I had realised for a change of date to the following monday and gave her my number to contact me as she told me her phone got confiscated by the teacher and I told her she could probably comes w her friend so she still could contact me. I arrived slightly earlier, just in case she had reached earlier. I waited for her 20-30mins with my friend at Khatib mrt and dont see her at all. I left after waiting as my friend and I are rushing to Singpost to mail out my customers' mails. I fb msg her the moment Im home to notify her that I left after waited for her but unable to meet until her. Our schedules kept on crushing. She asked me to opt for postage, after much persuasion from her, I decided to go for postage. I asked her for her bank account and then she told me she doenst own one and asked me to do conceal cash. Absurd much? $100 conceal cash, if lost then who would be responsible for it? She said she would be and then I told her, I would only do a deposit, she was nego-ing with me for the deposit amount because she claimed that she needs it to do refund. She owes customers' money then she should had spare money to do refund and not wait for money to comes in to do refunds. After that, i did mailed out the postage of deposits but she did not received while ALL the postage I had mailed out to my customers all received it safely. After that, from what I normally do, I throw away the receipts because all are accumulating in my wallet and since my customers had notified me they had received their parcels, I see no point keeping them. I dont stay in contact w her because I only used my fb acc once in a blue moon as I had a new account and see no point using the old one since I have no idea who the majority of my friends in the friend list are.

She wa me yesterday, probably know it through my fb comment. After that, she kept on arranging for meet-ups and keeps on asking meet-ups for the same day after I had repeatedly said Im not free. I blew my top after nearly 6 hours of wa w her because she sounds as if shes my mom, even my mom dont control me in this way. I only got the wa conversation as I couldnt retrieve the fb conversation. I checked her fb wall yesterday after she contacted me. I found out that she had pm-ed me but she went mia-ed on her wall because there are people demanding refunds for sub-quality items and overpriced as well but she refused to reply. I asked for meet-ups and insist on it because I am afraid she might give me sub-quality things as well.