I guess you did nothing about it, so they will continue.

I donated once to a charity via a text message, they phoned me back (told me it was a thank you call but obviously they wanted more), I told them never to call me again. That worked.

I'm on oxfam's list, I just asked them in-store to never send me any more crud, they got that put on the system, never got anything more again.

If there is a problem, fix it, don't hope it goes away.