I'm currently on holidays, and I'm a software developer.
For the first time in my 10+ years of work, my boss tried to reach me during my holidays, on my private phone (while I have a company phone that I left turned off at home). It's not my project manager who would normally call me for daily emergencies, but my actual hierarchical superior with whom I interact between one and two times a month, sometimes less. He's the one who had the final word in giving my my holidays. I couldn't answer the phone because where I am, I barely have any network, and if I had heard the call, I wouldn't have answered anyways (because it costs me very much, being abroad).
Additionally, I contacted him once during his holidays, on his work e-mail, explicitly stating that the matter could wait until his return. That time, he answered me back within the hour. I didn't expect him to do so, and now I feel I have to answer him because of that, but I don't want to. I took all precautions to let him disconnect entirely. He didn't, and now I feel he expects me to not disconnect entirely as well.
I want to enjoy my holidays to the fullest and would like to send a text message to tell him to stop trying to contact me and that I will deal with whatever he wants upon my return, just like my "Out of Office" message says. How to professionally formulate anything that will convey my ideas?