There is an extremely simple rule for dealing with reviews that make you unhappy. Here is the rule: it's not them, it's you. This rule of thumb implies, it is never the reviewers' fault. Rather, it is always your responsibility.
Oh, you say the reviewers didn't seem to understand the paper? Well, that's your fault. It is your responsibility to make sure the paper is comprehensible to its intended audience. If the reviewers didn't understand the paper, odds are that the rest of the readers of that journal/conference won't either. Maybe you need to do a drastic rewrite to make the paper more understandable. Or, maybe you submitted the paper to the wrong place.
The reviewers didn't seem too excited about the paper, and they gave you a short one-line review, or they focused on nitpicky comments about grammar and didn't say much else? Well, that's on you. It's your responsibility to convince readers that your results are significant. Maybe your paper's results just aren't up to the level of significance expected at that journal/conference, and you should be submitted somewhere else. Or maybe the paper didn't adequately make the case for why people should care about your results.
Why this rule? Because authors are notoriously poor at seeing the shortcomings in their own work. No parent thinks their own baby is ugly. When you get negative reviews, it is natural and human to assume the reviewers are idiots and too blind to see the brilliance of the work sitting before them. Well, that's fine. Take a moment to curse the reviewers, and get it out of your system. Then calm down, and think more rationally. It is rare to find cases where reviewers are stupid or lax in their duties; it is much more common to find that there is something valid behind their reviews.
Realistically, if the reviews are negative, the most constructive thing you can do is improve the paper and re-submit (possibly to somewhere more suitable). There is almost always some way that you can improve the paper and that you can learn from the reviews you got back.
I realize my rule might seem like an oversimplification. Well, technically, I suppose it is, but it's a lot more accurate than most folks who are new to the field realize.
In my experience, complaining to the editor rarely leads to any positive result. I suppose that in the most extreme of cases, it could be warranted, but I would have a heavy presumption against that. And, you probably don't have enough experience to form a judgement on that. Before complaining to an editor or appealing the decision, sit down with someone much more senior and more experienced and ask for their advice. If they are skeptical or neutral, don't bother complaining; just improve the paper and submit it elsewhere. Only if they tell you that complaining is the right thing to do should you consider complaining to the editor.