Alexander Obiefule (pictured), 30, worked at the call centre in Bournemouth where he was required to obtain account numbers from customers so they could make mortgage payments.
Between July and November 2016, he used bank details of those he spoke to on the phone to carry out 52 fraudulent card transactions totalling more than £4,900.
Two complaints from customers were received on 22 November 2016 who said their bank cards had been fraudulently used following a phone call with Obiefule at the call centre.
This was reported to Dorset Police on 23 November 2016 and officers went to the call centre that day to arrest Obiefule.
An investigation was launched by officers, who worked with the Nationwide Building Society Fraud Unit, and another 11 victims were identified.
Obiefule was re-arrested in April 2019 and made full admissions in an interview with the police. All 13 victims were refunded the money they had lost.
Obiefule was sentenced to 26 weeks in prison suspended for 12 months after admitting 13 counts of fraud by false representation at Poole Magistrates’ Court on 5 November 2019.
He also was sentenced to 250 hours of unpaid work and up to 15 days rehabilitation activity requirement.
A spokesperson for Nationwide said: “We take employee fraud very seriously and have robust procedures in place to detect such incidents and activity. We will always assist the police in securing a prosecution where appropriate and we are pleased that in this instance the law has taken its course.
“We have fully refunded those members who were the victims of this incident and we have also reminded employees of their responsibilities and the potential implications, should they commit fraud, or fail to adhere to our strict internal processes.”
Detective constable Rob Fletcher, of Dorset Police’s Economic Crime Unit, added: “Alexander Obiefule abused his position and used it to take money from innocent victims.
“We will do all we can to bring prolific offenders like Obiefule before the court.”