My complaint is solely getting texts on my cellphone that is not meant for that use about last minute plans (new plans, not plan changes) when it's late at night and I am home and my cellphone is away (or, prior to this thread, was away). I have asked my friends not to do this. It still happens.
It's even more frustrating when I know for a fact that they are also at home and could just as easily email me or contact me by any other more reliable means.
Just a thought, but you *are* using your phone for last minute plans because you are responding in the affirmative to plans friends are texting you last minute. One problem with this is that it almost sends mixed messages when you say, "oh, I never check my phone, so it's not the best way to reach me" but then they actually are able to reach you and make plans. So instead of registering as "Do Not Text Knitterly, because she will Never see my message," it might be coming across as "texting Knitterly isn't always the fastest way to get in touch, but for low key, informal, impromptu and non-essential things it is an acceptable form of communication". The first is something I would likely commit to memory. The second wouldn't make the same impression.
If it really is important to you that the change (and based on your posts here, it seems like it is and that's okay), it might be better to use actions rather than words to demonstrate how your preferences. If you were to start missing last minute plans, it might make more of an impression. If you miss a text until it's too late, say so. "Oh, I'm bummed I missed your text. In the future, I'm far more available via email address." Another way to show not tell is to always reply by email or phone. Never answer your cell phone when you are home. Even if you hear it, let it go to voicemail and/or look at the number calling and call them back on your land line. Explain that you are conserving your minutes and add that the land line is usually the best "first contact" number for you (reminding them of the number if necessary). Make it *more* convenient for them to contact you by your preferred method.
Right now they clearly prefer to text you. You say that you know for a fact that other means of communication are equally convenient for them. But unless you are them, you can't possibly know that for a fact. For example, from the other side, checking a cell phone for text messages is exactly as convenient as checking your email. You could even set the phone up next to the computer. But, you have clearly stated that for you that is not the case. And I believe you. So it is worth considering that even if you don't understand why
texting is more convenient for them than emailing, that it is in fact more convenient for them.
As an example, at one of my first internships there was an employee whose mother liked to call his cell phone almost every afternoon with some question or other. It was the type of environment where answering personal calls was okay. But the problem was, cell phones were still relatively new and minutes were very expensive. She'd run his plan out of minutes in under a week. She had been given the work number (also okay), but just didn't want to call it. So he started not answering when she called. She'd leave a voicemail and then he would check it using the work land line. He'd also call her back on the land line. It took a few weeks, but guess who finally started calling the land line?