Unfortunately, the cage you have sounds very unsuitable for any hamster, and the chewing is likely in response to it; he's bored because he doesn't have enough room. You and your parents also seem to be victims of stores being untruthful when it comes to hamster care.
A suitable cage for any hamster should be at least 80x50cm, but preferably 100x50cm. Continuous horizontal floor space is a lot more important than vertical space. Having too many levels can be bad, as hamster are not good climbers (no matter what they think!), and a fall can do a lot of damage.
Pets at Home sell the 'Hamster Plaza' for £80, which is a very good cage, and one I use for my Syrian. They also sell the 'Hamster Heaven' for £75, and I think I've seen it on offer for £55 a few times. If you're into DIY at all, you can likely make something much cheaper using a suitable sized storage box, or something from IKEA (The Dettolf used to be a popular DIY cage).
The wheel for a syrian should be at least 11inches/28cm, with larger syrians needing 12inch wheels. I currently use Nightangel wheels, which are on the expensive side, but there are cheaper wheels by Trixie and Bucatstate that are suitable.
The 'hamster balls' should not be used at all, as hamsters are almost blind and rely on their whiskers to 'see' where they're going. They can't 'see' in the ball, so any time they crash into something, it's just scary. He's probably panicking inside it, rather than enjoying it.
You could have a look on youtube for suitable DIY toys you could try making to help with Ralsei's boredom.
SomethingAnimal has a large number of DIY projects, and DIY cages, that might interest you. There are plenty others as well, but Ollie's is the one I'm most familiar with. =)
Sorry you're having so much trouble with little Ralsei. The start-up costs for hamsters can be a lot, but it is very worth it in the long run, as you can use most things for multiple hamsters. Also, please don't take anything I've put above as judgement. We all started somewhere, and this is just some guidance to help you work out what to do to help Ralsei have a happy life with you.