I am also a very recent customer (not connected with Seeed) but my experience is just the opposite to yours and I am very pleased with my purchase, so I wanted to put a balancing view in here.
Maybe it is mainly to do with expectations as I had researched this well and had got the manuals before I made the purchase. I therefore knew that that there was not a comprehensive, “all in one place”, manual and that this was not a product from an established instrumentation supplier but more a kit intended for those prepared to put some effort into making it work for them. I had noted, in particular, some bandwidth concerns around the front end and the battery installation confusion with the early models but this was not even an issue for me as my battery was pre-installed and I was prepared to deal with bandwidth extension if I wanted to.
What had attracted me in particular was the value for money and the open source nature of both the hardware and software design of the device. The latter is what can turn the Quad into a very useful and interesting device. I have already changed the base software to the community version (thanks Pedro and all the others) which makes it easier to use. I am now experimenting with the Pawn scripting capability (jpa).
It sounds like you were expecting a fully polished professional instrument out of the box. I can see why you may be disappointed if that was the case and I hope you either get your money back or learn a bit more about the virtues of the product. Having said that a scope is a specialised piece of kit and I would expect most people to research it well before making their purchase.