Yes I did. And yes I have.
In fact it was a major contributor in helping me to sell the company and retire.
Registering a trademark costs less than an authentic mod. Couple hundred bucks.
Sending a C&D letter takes another hundred bucks if you want an attorney to write and send it.
It's not hard or expensive, if you are legit.
Patents on designs do cost a lot more, (few thousand) mostly due to the legal research involved in proving you own (actually, prove no one else owns) the rights.
I had several trademarks and a design patent.
You did not register an international trademark for a couple hundred bucks.
You did not send a C&D letter to a Chinese cloner for a hundred bucks.
You did not obtain patents in 196 countries for a few thousand.
I assume svoemesto is "legit" so they must lazy and or cheap.