Hello, ­­­­­

I am just checking about the progress of this issue. Let me know If you need my further assistance on this  matter?

Thank you for using Infragistics Components.

The chart's theme has control over axis font, so in order to change the font you'll have to create a custom theme. Here's an example of a custom theme. It's a copy of our IG theme. If you don't need series brushes to come from a theme, you don't have to include any of the IGChartPaletteItems; they're just the default series brushes.

if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPhone)
{
   _chartView.theme = [CustomChartTheme IPhoneTheme];
}

@implementation CustomChartTheme
+(IGChartThemeDefinition*)IPhoneTheme
{

IGChartThemeDefinition* def = [[IGChartThemeDefinition alloc]init];
def.name = @"IGChartIGTheme";
def.font = [UIFont fontWithName:@"Helvetica" size:12];
def.fontColor = [[IGBrush alloc] initWithR:0 andG:0 andB:0 andA:1];
def.backgroundColor = [UIColor whiteColor];

def.legendFont = [UIFont fontWithName:@"Helvetica" size:12];
def.legendFontColor = [[IGBrush alloc] initWithR:0 andG:0 andB:0 andA:1];
def.legendBorderThickness = 1;
def.legendPalette = [[IGChartPaletteItem alloc]init];
def.legendPalette.name = @"legend";
def.legendPalette.color = [[IGBrush alloc] initWithR:0.9 andG:0.9 andB:0.9 andA:1];
def.legendPalette.outlineColor = [[IGBrush alloc] initWithR:0.7 andG:0.7 andB:0.7 andA:1];

IGChartPaletteItem* item1 = [[IGChartPaletteItem alloc] init];
item1.name = @"item1";
item1.outlineColor = [[IGBrush alloc] initWithR:0.14 andG:0.50 andB:0.66 andA:1];
item1.color = [[IGBrush alloc] initWithR:0.27 andG:0.67 andB:0.84 andA:1];
[def.seriesPalettes addObject:item1];

IGChartPaletteItem* item2 = [[IGChartPaletteItem alloc] init];
item2.name = @"item2";
item2.outlineColor = [[IGBrush alloc] initWithR:0.2 andG:0.2 andB:0.2 andA:1];
item2.color = [[IGBrush alloc] initWithR:0.29 andG:0.29 andB:0.29 andA:1];
[def.seriesPalettes addObject:item2];

IGChartPaletteItem* item3 = [[IGChartPaletteItem alloc] init];
item3.name = @"item3";
item3.outlineColor = [[IGBrush alloc] initWithR:0.5 andG:.5 andB:.5 andA:1];
item3.color = [[IGBrush alloc] initWithR:.66 andG:.66 andB:.66 andA:1];
[def.seriesPalettes addObject:item3];

IGChartPaletteItem* item4 = [[IGChartPaletteItem alloc] init];
item4.name = @"item4";
item4.outlineColor = [[IGBrush alloc] initWithR:.09 andG:.32 andB:.44 andA:1];
item4.color = [[IGBrush alloc] initWithR:.13 andG:.43 andB:0.6 andA:1];
[def.seriesPalettes addObject:item4];

IGChartPaletteItem* item5 = [[IGChartPaletteItem alloc] init];
item5.name = @"item5";
item5.outlineColor = [[IGBrush alloc] initWithR:.53 andG:.6 andB:.13 andA:1];
item5.color = [[IGBrush alloc] initWithR:.64 andG:.73 andB:.16 andA:1];
[def.seriesPalettes addObject:item5];

IGChartPaletteItem* axis = [[IGChartPaletteItem alloc] init];
axis.name = @"axis";
axis.outlineColor = [[IGBrush alloc] initWithR:0.60 andG:0.62 andB:0.64 andA:1];
axis.color = [[IGBrush alloc] initWithR:0.60 andG:0.62 andB:0.64 andA:1];
def.axisPalette = axis;

return def;
}
@end 

Hope this helps you.