My wife booked a tab cab a day before. She also updated her mobile number(the old number was disconnected). she was assured availability. Surprisingly the next day morning was a series of followups because apparently tab cab had not provided the driver with her updated number.
She called TAB cab and obtained the drivers number, but the cab driver was constantly disconnecting the call. To our surprise the new number was not even registered. After a long 2 hours struggle they could not even make alternate arrangements on time.Finally a local taxi was called.
After about 15 days my wife registered herself as a new customer with TAB cab with her new mobile number. This time the cab arrived on time.
This is a typical example of a process failure. Procedure needs to be in place for updating clients master details.