It seems to us from reading over your comments a couple of times that you have already made up your mind what you want to do. Your comment -- "I don't know how long I can stay in this field without being completely irritated at the lack of intelligence" -- speaks volumes about how you feel, especially when coupled with your comments about how practical and connected you feel human resources is with your undergraduate studies.
If you try to base your decision solely on what others tell you about any chosen field, you'll continue to be confused. You can find those who love the area you're considering and those who think it's no good. There will be no shortage of opinions on either option. So, rather than let others try to make up your mind for you, often with erroneous information that isn't based in fact (what's boring to one person might be intriguing to another!), do a little more research into exactly what's involved in getting a degree in marketing/communications and what kind of job options there might be when you're finished. Do the same for a degree in HR.
Only after you have a better grasp of what each area would offer in terms of a study program, skill content and future job possibilities, (assuming it's still interesting to you), should you go ahead and talk with people currently working in each field about their experience. Keep in mind that your experience wouldn't be identical to theirs, but sometimes it's helpful to hear what others have learned and see if their wisdom can help you decide the best possible course of action to take. Act like a sponge and gather up all the information you can about each option and then sit with this information for a few days to digest it. See what option feels like a better fit with your passions, personality and goals. As you contemplate starting this research, you'll know immediately if you greatly favor one option over the other by how much enthusiasm you feel for each!