I have multiple experiences with warehouse/storage/distribution side of big IT upgrades and conversions. Two, in particular, took months to fully recover. But, others were nearly seemless.
As someone (ones?) mentioned earlier, thorough testing of every application with REAL data in a test environment goes a long ways. Also, suspending orders for a day or two at update go-live can be a huge help. CBID customer service has always been outstanding. In fact, there have been a number of very bad warehouse ops periods, in which, I believe CS actually saved cbid by making up for the negatives. I have no doubt they are doing what they can, but TG is undoubtedly correct that the volume of complaints/inquiries has overwhelmed..the phones, the email, the people...