I read the linked post and it got me thinking of a lot of the posts I typically see around Linux. Most of them that are seeking support are very distro focussed; what is the best distro for this, what distro should I choose, etc.
The post I have linked shifts the focus to a clear use case putting the distro element in the background. I found this more useful, as I think, for the most part, the 'right distro' is subjective. What works for one person may not be right for another based on so many factors.
So, I wondered if anyone has any really interesting use cases around Linux. Especially those that can debunk the idea that you cannot do this, that and the other on Linux. Anyone using an audio production setup, has a video development suite or runs visual graphic design from Linux or, do you just have the gaming rig nailed down!
It has already been said but the company is complying in the sense that it is providing a solution whereby you can delete your account. That said, where you are unable to follow that process, they should offer you the same ability via email. Each company does things slightly differently but I would hazard a guess that an email stating that you find it more reasonable for the action to be carried out via email, they would be likely to comply.
The reasons why companies put these in place is simply to avoid mass requests for deletion and, as stated, to also protect you.
While email spoofing has been mentioned, it is somewhat unlikely anyone would send a request for deletion after spoofing your email, yet, it is not impossible.
You may have to be persistent, could use services that support or even get some pointers from the ICO. Here is a really good link https://ico.org.uk/for-the-public/your-right-to-get-your-data-deleted/
I wish you luck