I have ordered many IEM from them and never have a issue of delivery or products. Customer service is one of the best and always there to help out.
Warranty claim is also very easy actually. Two of my IEM was not working I send it to them (you will have to courier it at your own cost) they provided the replacement for one and repaired the other one.
I find headphone Zone currently the best and safe place to buy headphones and IEM because my overall experience with them has been very great.