Ajax did not receive a call-up for Billiat or team-mate Tafadzwa Rusike from the Zimbabwe Football Association despite both being named in a 20-man squad last week.
Ajax said they had only read about the call-up to the game at the Rufaro Stadium for the duo but would not let them go because ZIFA had no sent a formal request.
FIFA rules state that any club that does not receive a call-up for a player 14 days before the date of the match is not obliged to release the player for the match.
But after trials with ZIFA on Thursday, Ajax agreed to let Billiat travel to Harare to join up with the team. Rusike, however, has been injured for several weeks leaving Ajax officials bemused about how much preparation Zimbabwe actually put into the formulation of their squad.
Ajax chief executive officer George Comitis said Zimbabwe were consistently late with call-ups.
Zimbabwe team manager Sharif Mussa admitted: “Of course there were problems here and there and that is one area we need to improve on, in terms of communications.”
Zimbabwe have called up a total of 10 South African-based players for the friendly match.