Was the retailer not familiar enough with the product to coach you on install and help you troubleshoot any problems? It sounds like yours may have had a couple of quality issues, rest assured ARB's tech department will solve those, however in regards to the install its my personal beleif and this proves it that ARB is not a end-retailer, hence why they don't sell direct to the public and in fact sell through a dealer network that they expect to be proficient and knowledgable on their product. Would not have solved all your problems but maybe some of them?
I've personally dealt with a handful of the mosquito nets, no issues to speak of. I'd give your retailer or ARB's tech department a call on Monday and see what they can do to sort it out for you. If nothing else your issues will prompt future solutions. The improvements between the Simson II -> Simpson III and even more so on the Simpson IIIB has been parralleled by their awnings and related products. User feedback is fundemental to that improvement. Good luck!
Halve the retails stores are owned by ARB