Hi @chatlanin2006 - Sadly, developers are no longer working on SimCity, so there won't be any more patches or updates. If you just purchased the game and you're still in the return window, you can probably get your money back. I still enjoy the game, and even though there are a few bugs, after playing it for many years I've decided that I enjoy it enough to work around them. ymmv That being said - Megatowers can be really tricky. Two important things to remember: Megatowers are not stand-alone cities, and Megatower changes take a long, long time to update.
Because they're not stand-alone cities, the whole city's population data makes a difference, not just the levels in the Megatower. I know it doesn't make sense that the Sims would travel down past the mall and out to the city to go shopping, but they will. If you just put the apartment level in, it could just be that you need to wait a few more Sim-days or months to see the mall stop complaining. Or, you might have too many commercial buildings or parks in your city and so the mall is not getting enough shoppers. Parks, landmarks, gambling and events will also draw residents out of the Megatower.
Keep an eye on your population details and try to keep the number of unsatisfied shoppers to zero and unsold goods to around half or less of the total goods. If you have too many unsold goods, demolish and rezone some of your commercial to residential or industry depending on your city's needs. Same with workers - try to keep your unfilled jobs to about half or less of the total jobs available. Once your data says your city is well-balanced, you still will have a wait until the Megatower notices the changes. In the meantime, it's hard, but just ignore the warning messages and keep playing by the population details. Not all messages need to be heeded. They're annoying, but they don't always point to the right problem. ("not enough shoppers" might actually mean "traffic jams are stopping Sims from getting here")
Personally, I rarely build anything but residential levels in a Megatower, and never mix wealth levels in the towers. I use the surrounding areas for commercial or parks, instead of the levels. Remember that the Megatower itself will raise the land value around it, so it's important to keep an eye on the wealth levels of parks and commercial buildings. And I admit to not having a lot of patience - there are so many times when I've had all of the residents move out of a residential level - mine's usually because they can't find work or are overworked - and I just didn't have the patience to wait months while new ones moved in, so I just demolished the level. Sometimes, logging out of the game and then back in can be useful because it resets traffic and gives you a chance to watch traffic patterns and Sim movements to see where the residents are going.
You just need to build slowly, watch your numbers, have patience (or a lot of simoleans to demolish annoying levels) and ignore complainers when they don't have anything to complain about anymore. Happy building!
