Actually I really liked the service from this company.
I bought my shower filter from them probably a month ago and the shipping was free. It arrived in a couple of days and I just installed the shower filter easily. It's pretty much hassle free. I wrote them a review and emailed it to them (as they asked for one) and they put it up on their website.
It's a shame you had a bad experience - but I found it all together quite simple and straight forward. Have you let them know you're unhappy with them yet? If not, you should let them know. Better to have open lines of communications to resolve problems I think! :)