1) It takes at least a full 2 weeks to receive your online order. And theres a very tight return timeframe already.
(It's also hard to plan payments on debit cards for 2 weeks later, when they finally deduct your money.)
2) The customer service reps are usually poorly informed, and rarely show any understanding or care.
3) There are glitches in the system: on multiple occasions, I got erroneous emails every 2 hours for days on end, until customer service responded to correct it. (And often, it takes repeated contacts for them to understand and fix it. Then, they don't offer any apologies.)