…Even a math Phd student could not figure them out.  True.
According to consumer watchdog which? and reported by Paul Farrow in the Telegraph bank overdraft charges in the UK are so complicated that even a math Phd candidate did not get all of the calculations correct.  It further found that practically no ordinary bank customers could figure them out.

The study found that due to their complicated structures it is virtually impossible to calculate the overdraft fees as well as it being practically impossible to compare the charges between banks.

In the test a group of customers was given mock bank statements and asked to calculate the cost of an unauthorized overdraft at four different banks.  Between them they got seven of 48 calculations correct.

The watchdog wants the new financial regulator, the Financial Conduct Authority, to stop unfair overdraft charges, with clear powers to tackle excessive fees and complicated structures.
Peter Vicary–Smith, the chief executive of Which? said, "It's extremely disappointing to find that bank charges are still too high, too complex and impossible to compare."