I'm the technical leader at a software development company, and my boss instructed me to rush the team for implementing various changes on a system that were informed after project release, since the data needed for this change had to be provided by the client's workers, and was going to be used in a presentation for the directive board so it had to be implemented fast.
We requested the data with anticipation via email, but it was shared by them after work hours one day before the presentation and it was in the wrong format. I stated to my boss that the data was wrong and that even if we could fix the format there was a high risk of creating system failures and that the development team did accomplish their tasks, but he said we just needed to make the necessary changes and I should ask the team to stay late, an instruction I refused to follow and lead to an argument.
Things like this are becoming a norm working with this client, their personnel responds late and we are asked to rush for changes, for me it's unfair and caussing problems with the team. Since I'm the second in line of command, what could be the best professional way to handle a meeting with my boss and show that this customer relationship is wrong?
Regarding how communication was handled. I sent an email five days before the deadline as soon as I got the assignment. Attached in the email was the file example in the format required. Then I followed up by making phone calls and sending WhatsApp messages from the company line but got no answer whatsoever and no one returned calls. I didn't send further emails about this until I got the response.
Reviewing the answers, I'm updating the question to ask what solutions could I present to my boss for this issues, since is more helpful and constructive than proving a point as my original question intended.