I think you may have incorrect/unsuitable expectations of your guinea pig... The truth is that guinea pigs don't really "bond" with their human owners in the same way that -- for example -- dogs bond with humans. Many pigs will become familiar and more trusting of their human caretaker over time, but some will always remain skittish and shy. Guinea pigs really need the company of other guinea pigs far more than they need the company of humans. They are adapted to live in herds and although guinea pigs don't really "bond" closely with one another either, having others of their own kind around is key to helping them feel safe and confident in their environment. Often, owners who think that their guinea pig is just naturally skittish and fearful will see an improvement once the guinea pig has a friend. I understand, though, that getting another pig is not an option at the moment in your situation.
All that being said, you've only had your pig for a few days. It nearly always takes a MUCH longer time than that for a guinea pig to adjust to her new home. She's likely not ready to interact with you yet because she's still getting used to her new environment. If you say that she's more comfortable coming out when you moved her cage up on the wardrobe, then try leaving her up there. Having some height so that humans aren't hovering above them definitely helps pigs feel safer.
As for the eating, again, this is something that would be much more easily solved with the introduction of another guinea pig. Most people incorrectly believe that guinea pigs instinctively know how to eat vegetables and hay. This is not correct. Guinea pigs actually learn what's good to eat by watching what other guinea pigs eat. It's a much longer and more difficult process to teach a pig to eat veggies without another pig, but there are ways to do it. Here's a link that may help:
https://www.guineapigcages.com/forum/threads/105287-How-to-teach-a-guinea-pig-to-eat-vegetables Maybe getting her up on the wardrobe will make her feel safer and she'll start coming out to eat more often now. You should also evaluate the quality of the hay you're giving her if she won't eat it, and maybe try switching to a different hay. She absolutely MUST eat hay -- it is the single most important part of a guinea pig's diet.
Also, exactly what kind/brand of pellet food is she eating? By muesli, do you mean seedmix? Guinea pigs should NOT be fed seedmix; it is not a suitable diet. The only two pellet foods that we recommend on this forum are Oxbow Essentials Cavy Cuisine/Performance (one is for adults, the other for youngsters under 6 months) and Kleenmama's Hayloft Timothy Choice pellet food. I'm sure the Kleenmama's probably isn't available in the Philippines, but maybe the Oxbow is? If not, guinea pigs can go without pellet food as long as they have a suitable variety of high-quality fresh vegetables and fruits and good quality hay. Pellets are the least important part of a guinea pig's diet, and no pellets at all is better than feeding her an inappropriate pellet food.
Finally, here are some links with information for new guinea pig owners:
https://www.guineapigcages.com/forum/threads/107827-What-NOT-to-do-for-your-guinea-pigs
https://www.guineapigcages.com/forum/threads/113176-Information-for-new-guinea-pig-owners