I got a cheap ER32 collet set from Amazon. Fortunately I had read on another forum how someone had to chuck the closer nut into their lathe to make it concentric. I don't know if this is the same problem you had but once I trued the closer nut up it works as good as I would expect for $44.
Most Chinese eBay sellers don't want anything back, or to give any refunds, go figure. I had one sell me a VFD that was under the capacity advertised in the listing. After going back and forth with them (please send a picture, please send a picture, etc.) I just told them how much money to refund to my PayPal.
This is the approach I would take with any Chinese suppliers, if their description matches what you got they will consider themselves to be in the right. If it doesn't, they will still consider themselves to be in the right. They know they're selling to a price point and you can be sure there's plenty of profit for them even as cheap as they're selling for. It's a matter of volume, and refunding you part or all of your purchase price is just part of the cost of doing business. The person who answers your email doesn't have any idea of what you are doing with the widget they sold so don't expect that. Also, try to work with a percentage of the price you paid. Doing the currency conversion isn't as easy as saying here's a 20% refund. Also, don't expect the threat of a negative review to phase them, eBay sellers know how to manipulate the system with multiple profiles.
I learned a long time ago when a Chinese woman blatantly cut in front of me at the grocery store that they aren't operating under the same rules we (most westerners born before 1980) were taught as children. It's not that they aren't decent folks, they're just working from a different cultural playbook.
So, as has been said so many times on the forums. Chinese tools are best considered "kits". You'll probably get most of what you need to make it work but don't expect them to perform straight out of the box. If you have the budget definitely patronize one of the better suppliers, US or otherwise. There's definitely good stuff out there for those that are willing to pay.
Cheers,
John