The first, thank you for purchased our module. I don't know why you write negative review. All description of our module is clear and we also give you live demo and you can check it before purchase. If you don't like our module, you don't need to buy it.
I don't know what is the problem you get. However, we are reply your topic after some hours, not 3 days as you wrote. Just check our forum here: http://vinaforum.biz/joomla-modules/436-tcvn-slit-slider-released.html
Before you post a negative online review, just contact me and let me help you solve your problem. Because you can kill a product with just one your negative review.
You can use the free support forum section. Uhtred (a friend of mine) answers almost every question there, so it's not true what you've said. You just have to register and activate the free support subscription. That's all!
If you use an older version of the component, then you should install the plugin EasyCalcCheck Plus which stops every spam.
With the latest release of the component (2.5-3) you won't get any spam, even without ECC+. I use the component on the demo site and had not one spam entry from bots!
Thanks anyway for the review!