Alfordson Ergonomic Executive Office Chair

This chair feels unstable and is cheaply made. Screws and caps are already falling out and I've had the chair only a month. The backrest is in a reclined position and does not go up into a 90degree angle. Therefore...my back is NOT supported when sitting and using a computer at a desk. (see attached photos). At times when I'm typing on my computer I need upright back support. That option should be an available choice if needed to avoid lower back and neck pain while working on the computer.

I bought the Alfordson Ergonomic Office Chair Executive White and Grey from Bunnings Marketplace. They claim to have TUV compliance on the casters, although a search on the TUV Rhineland Australia site. A month or two after purchasing the chair, I noticed that the wheels were at a strange angle, and they have now completely collapsed. Upon further inspection, the plastic is weak and the pinion as ripped a hole through the side on all of them. The armrests don't lock, so if you lean on them they click outward. Don't rest on them when getting up, you'll go flying. All of the locking parts have started to loosen up, and the chair 'gives' to an awkward backward angle. I contacted Bunnings Marketplace, but their attitude was that this isn't their problem telling me to contact the seller. I got a reply (attached below) from a gmail account supposedly from [Name Removed], but signed "Echo". Their website claims to be selling the chairs at an 81% discount down from $999.99, however, all the "marketplaces" are selling it for around the $170 mark. Their return policy is that I am responsible for shipping, making it more expensive to return it than to buy a new one.