I installed MacKeeper some two years ago. Instead of improving the use of my Mac computer it made it utterly unusable.
The salesman, a certain Mr. Michael, had promised help if I should need it if I sent an e-mail.
MacKeeper responded to all my my e-mails pretending I had sent them an 'empty' e-mail.

I carefully checked and found out that scores of e-mail messages I sent we all duly received everywhere except...by MacKeeper.
My Mac is unoperable since then. I cannot afford to pay for repairing my Mac. And found it cheaper to use an old PC instead.
When offered to renew my license, I expressly made it clear that I did not wish to renew my license and gave the reason for it.
I asked not to charge my credit card anymore and asked never to have any business with MacKeeper anymore.

Yet while reviewing my bank statement I was surprised that in spite of my written request, MacKeeper still charges me for the sum of 88.95 $.
Earlier this morning, I sent two e-mails with the request for a refund. But my e-mails were ignored.
I tried many, many times to call them. It seems that they have blocked me because their line is always busy. 

This is a copy of the e-mail I wrote to on 8/10/2015 to Mr. Michael from MacKeeper with my refusal to renew my license:

Michael,

I do NOT wish to renew my license.
I imagine you know why and that this comes to you as no surprise.

Three four or five times I needed help. I received none.
I sent at least three or maybe more e-mails only to be answered that MacKeeper has received an empty email. REALLY ?
MacKeeper was the only one who has received an empty email from me. I tested the same email sending it to four different addresses. EVERYONE received the message with no problem at all.

This an old trick used by rogue software.
You have succeeded at conning an elderly and needy person.
Congratulations !

Remember however that such a behavior will bring inescapable ill-luck to its perpetrators.In despair I started to search the web. OMG It became clear that I was only one among many othersGo ahead and read the suff  if you have the gutsAND don't ever ask me to have any business with you again and please confirm that you will not ever again charge me for any payment at all. EVER .
signed....