Not fallacies
###Not fallacies FallaciesFallacies don't apply in this situation since they're not attempting to formally prove that you're wrong or even asserting that you must be.
This goes doubly so for:
If you don't like it then why do you use it?
Here, they're not making a statement. It's not even a bad question - if you don't like a product, then potential buyers might have good reason to be interested in why you use it despite not liking it.
###Rudeness isn't ad hominem
Rudeness isn't ad hominem
There's a somewhat common misconception that rudeness is a fallacy; it's not.
Ad hominem is where someone reasons something like:
Bob said X.
Bob is smelly.
Therefore, X must be false.
The fallacy isn't in that calling Bob smelly is rude; as far as logic goes, that's perfectly fine. The problem's that Bob's odor doesn't typically have anything to do with statements he might make, e.g. X.
That said, it's still possible for this to not be a fallacy. For example, if it's:
Bob said that he's not smelly.
Bob is smelly.
Therefore, Bob not being smelly must be false.
That's not a fallacy because Bob's smelliness is relevant.