I've been buying from Banggood for almost two years now and had always had very positive experiences. In fact, a year ago I even wrote a very positive endorsement in the "Owners Feedback on Vendors" forum called "Banggood Kudos" after they were so courteous, helpful and prompt about replacing a bad "B' module I received from them. Something has changed for the worse over there. At first I thought it was just a bad staff member I was stuck dealing with but at this point it has become clear that it is just how they do business now. Also, a lot can depend on the popularity of the particular item you happen to be ordering. Ironically, I witnessed the same phenomenon at DX (Deal Extreme) several years ago. They were a great company to do business with but now it's a crap shoot. My theory is that it has something to do with what happens when Chinese retailers like this reach a certain size.
BTW, don't ever think for a moment that the names we are given by these customer service folks from these Chinese vendors are real.