Unjust written warning

It is regarding an Online ESL company wherein the tutors and students communicate via skype. The scenario of my problem is that I got a written warning despite following the SOPs set by the managing company. It is stated in the SOP that in case the student is offline to try and call the student is skype then submit an automated report in the website that the student is not answering the calls. The lesson time ended with the student not answering the calls so the student was marked absent. After a couple of days, I received a complaint that the student said that I did told him that I wasn't feeling well and I cannot conduct the lesson. I send all the screenshots of the call logs to the company to show that the student was not answering the calls. But despite doing that, the company still did give me a written warning. I just followed their SOPs but I still received a written warning which is I assume that is unjust. Do I have a claim against them? I do have the copy of their SOPs and proof that I just followed all of them.

you better ask your Head trainer first and then settle the matter with the HR or any person who is responsible for sending the written warning maybe there were misunderstandings.

First off ni warn ka lang naman, meron na bang sanctions against you? Anong naksulat dun sa warning?