Even if this was a valid tactic, does this person not realise the person on the other side would actually need to be able to read what is written for them to action anything?

Not everyone has nice handwriting (I sure don't), but you should at least try to actually be legible - that bit in the middle is just barely legible to someone actually trying to read what it says.

Also, not everyone who sends mail to you has to have a contract with you (and certainly not an international contract), especially not for a summons. This kind of letter isn't asking you nicely, it's telling you what"s gonna happen, and you better listen.