> when I said "un otro" just pointed like "get it yourself"

I can understand why. Next time don't use that, is incorrect (would translate as a strange "an, other"). The correct way would be either just "otra" (another) or "una más" (one more), generally followed by a casual "por favor". Take in mind that beer is feminine in spanish so you have to use "otra" (not "otro").

Many other alcoholic drinks are masculine, but are often served in a coup or bottle, that are feminine nouns. You can ask for "otro vino" or "un vino" but "una copa de vino" (a glass of wine) is also common. To use "un más" instead the correct "uno más" (one more) would be also a common mistake.