"Things I don't understand (but would greatly like to)

I have several accounts that comment on EVERY LAST Post of mine.
These accounts are very low rating, therefore are hidden, but they still show in the
comment count, being OCD about stuff, I have to go see who has commented,
what was said and therefore why was it hidden.
Without fail so far, it has been:

•[-]a-0-0 (-7) · 2 hours ago
Sell your votes (https blah blah)

[-]biblegateway (-4) · 12 hours ago
https://*****.com/news/*********6h36cq

[-]jesusisking (-2) · 12 hours ago
https://*******.com/news/@***** com/6h36cq

[-]biblegateway (-4) · 2 days ago
Go to @*****.com

I have gone to these profiles, I have MUTED each one, and yet
They still are able to come and comment on my post.

I have tried FLAGGING them, and since yesterday, the vote power
Slider is back, and I now know that if I flag someone's COMMENT
it costs me vote power!!!
How the hell is that fair?

Someone please help me understand and tell me what I can
Do about these low rep accounts that are SPAMMING my
Posts.
Thanks in advance for any and all help in this matter.

JES