Tradetang.com gave me whatever I needed to purchase. I only dealt with one seller trying to rip me off but other than that here my tips to get service from these sellers.
1. Ask LOTS of questions!
2. Clarify Questions.
3. Be direct when handling business.
4. Continue to message seller about product distribution after several minutes.
5. Check time zone in China.
6. Wait
7. Disupte if nothing is solved. This will result in the seller giving you what you want or a full refund.
8. IF you have a seller that you like... STICK WITH THEM!
AND lastly 9. Be patient... China's regulations are different than the US. I give it a 3/5 stars. Its not bad nor good, its average. The sellers NEED TO WORK ON COMMUNICATION IF THEY EVER WANT ANY BUSINESS!
Other than that... Tradetang.com has been somewhat of a blessing to me.