PivotChart Query: How to summarise data by month on the x axis

Hi,

I suspect there's a simple solution to this but once again i'm struggling to find it. Basically I have budgeted sales for a period and I want to plot the actual sales coming through over time. I've part achieved this on the attached example but the x axis looks a mess. How can I amend it so that it's summarised by month? I've tried amending the number format in the pivot table but this just brings back multiple instances of the same month, e.g. Apr, Apr, Apr, May, May May, etc. I've looked in the axis options but I can't see any way of amending the major unit to every month?

Thanks in advance,

Snook