Later audits discovered $1300 of MTA vouchers hadn't been reimbursed and $2668 of tobacco missing from the site.
In total, $10,975 of cash deposits were missing from BP Karori and $49,552 from BP Newlands.
In sentencing, Judge Peter Hobbs said it was clear Rudman's gambling addiction played a part in his offending.
"It was also exacerbated by your feelings of financial stress following you becoming aware that you were going to become a father."
Judge Hobbs said it was a significant breach of trust.
"You were an employee and held a significant amount of responsibility and by stealing from your employer, you have breached that trust."
In a victim impact statement, Rudman's former employer Rodney Earnshaw said the impact on the company was "far-reaching" and "distressing".
"Everyone is now on edge and on the lookout for possible discrepancies, delays and excuses.
"It is extremely difficult to impose and monitor perfect regimes to prevent such fraud - but nearly impossible when the fraud is committed by the gate keeper."
Earnshaw said they had to install security cameras in all site offices, which hadn't been well received by administrative staff who felt like they were being "spied on".
Judge Hobbs took Rudman's early guilty plea and lack of previous criminal offending into account when sentencing.
