Why do people NOT observe the rule, don’t phone?

Utility provider for my gas, now I am in the process of leaving them for another supplier that can provide customer service, is trying to phone me.
They have been informed by myself several times I am deaf and that email/chat is my preferred choice of communication.
They have also been told by my landlord when he had to intervene, to help get my gas sorted because of cutting me off from chat. They were obviously still asking to speak to me, or phone, because he kept reminding them that I don’t hear in the phone. (Whoever was on that end of the phone were thick, or deaf, to not understand clear instructions from my landlord.)
They don’t try once to phone me, they have tried a few times, regardless that I have them now blocked.

The charity that is collecting my furniture, they require a phone number, so the driver can contact me when he is half an hour away. I inform them to make sure the driver knows to text.
I had an unknown mobile number phoning me. I cancelled call and texted and it was them. They have done this before; phone, when I have given clear instructions to text.

Why do people ask for phone number, when you clearly tell them you don’t have one? Or because you say that is not my form of communication and explain why, that they still ask?

Even HMRC are not fully accessible. They don’t provide email as a choice to contact them and as I seen on Twitter, they don’t accept DM via there, due to security. But you can send a query via Facebook private message. That led me  to apologise butting in on this conversation, but I asked HMRC how can you say sending a private message via Facebook, is anymore securer than via a private message on Twitter? I query because I am deaf and you don’t do email, which is my preferred method. Whether HMRC will respond to this question, is another thing.

Businesses everywhere are stepping up, but HMRC are in the dark ages still, because they don’t do email. The same reason, because of security.

Where I now live, the doctors I have registered at, at time of registering, I discovered they were a little bit more accessible than my old doctors. Providing something that other did not and that’s emailing me, if they need to contact me.

It’s a simple request, when I say my phone number is for text only. Please don’t phone. Yet they try to phone?

But it’s not simple to those that I tell and it’s frustrating.