[gregjor]

I asked a friend who manages a call center now and has managed call centers for years, previously at a big US bank.

He said that sometimes they have multiple systems or outsourced call centers that don't integrate, and since the inconvenience falls on the customer no one at the bank considers fixing it a priority.

He then mentioned that customer service operators frequently get people on the line who don't have their account number or whatever they need ready, so having the phone tree collect that (even if it's just an input that gets ignored) heads off the operators wasting time on the call while the customer digs around for their account number or receipt number or whatever it is they need.

Having worked at a company that had an outsourced call center myself I know people often call the wrong company (calling their bank about their credit report, calling a store about insufficient balance on their credit card). And I know that even asking customers to enter their ZIP code or phone prefix (to route the call to a regional center) will flummox a significant number of callers. Because call center operators generally work with quotas and maximum time per call monitored, reducing the time the operators spend waiting for grandma to find her account number becomes an important goal, even at the expense of irritating some customers.