The magistrate convicted the pair after a full trial.
Mapanzure was facing 108 counts of fraud, while Guwu was facing 98 counts.
Mapanzure was sentenced to seven years imprisonment but will serve an effective three-year jail term if certain conditions are met.
Two of the seven years were suspended on condition of good behaviour while the other two were suspended on condition that he restitutes Econet of nearly $15 million.
Guwu was sentenced to four years, two of which were suspended. In his ruling, Maturure said:
In assessing the sentence, the court has considered that part of the stolen money was recovered.
The court is sentencing them separately because the second accused (Guwu) initially committed the offence with the first accused (Mapanzure) but later received money to buy American dollars from the latter.
Prosecutor Walter Saunyama said sometime in 2019, Mapanzure and Guwu connived to defraud their employer of $20 384 475. He said:
They replaced an Econet mobile broadband merchant line 0784953460 with a physical sim card. This enabled them to carry out Unstructured Supplementary Service Data (USSD) transactions by inserting the sim card in a Mobicel cellphone with serial number 359725084071720 and transferring money into agent lines.