Sold on Wedneday 7th, got bad feedback Today Sunday 11th

Hi, im genuinely wondering if I am in the wrong or not. 
I sold an item on Wednesday 7th, the buyer did not pay or send their address. I usually wait 3 business days for a buyer to pay/give delivery address. 3 Business days from Wednesday would've been today (Monday) Today I would've sent a email to confirm with the buyer if they still wanted to proceed with the trade or not. But instead I get a negative feedback at 10pm Sunday 11 August saying the buyer is unhappy with my lack of communication. The buyer also opened up a dispute with trade me to request their "help with completing the trade" but they buyer emailed me after they opened the dispute to let me know they don't want to complete the trade (so whats the purpose of opening a dispute?) 
(I did request the buyers address on Friday, as a sidenote, but did not get a reply)

My question is, am I in the wrong here, is waiting 3 business days too long to confirm with someone if they still want to complete the trade? Should I change my process to being 2 business days? Or was the buyer unreasonable? Overall, I just want to improve as a seller on trade me and learn from this. Thank you.