If you want to get some more specific opinions about Bitcoin transactions, you would have to provide more information. For example, which exchanges are involved, and which type of trade, do you have limits on your account? What kind of orders did you place so they were rejected? Rejected or something else, How much fee did you put, and how much was in the mempool at that moment...
There are many questions, and we know that you bought shoes and which company tried to deliver them to you.
The exchange is Binance, and it was selling and buying kind of trade, I don't have any limit in my account, in Binance p2p is free and there was no fee in it. Your questions are not related to the Op. It was simple analogy, I ordered a deal when the price was some how high, and immediately I ordered the deal and I was waiting for the buyer to buy but the buyer cancelled the order because the price of bitcoin came down (reduced), I ordered again and it was the same and the last was cancelled itself after the time has elapsed.
I appreciate all the comments, there are lot to learn and asked even on bitcoin, well to some extent the cancellation by buyers is not too bad because it is a business, and they need profit, one of them even ask me to reduce the price for him to pay me but I also refused. And the other hand, bitcoin is meant to buy things online and it mainly for p2p, and in such situation when you are in the malling shop and you want to use bitcoin to pay for the service, as some early bitcoiners did to buy coffee, and the process delay what will you do. Let us see meaning to this post and not only on the other way around. There are morale lessons in the thread. As other said, don't believe Centralized exchange and prepare yourself always for the unseen disappointments.