First off, lucky you to get a X4 qmiles offer!

The first of the two qponts offers you mention will apply to bookings made from the date you were notified of it until the 9th August, so that won't be backdated to your booking. But it sounds as though you may qualify for the second summer segments based offer, but will have to wait until the campaign ends to get the qpoints.

So that's a bit frustrating if it delays a tier upgrade, but I'm sure they'll turn up after the stated date (although perhaps a week or two after the stated date going on past experience). The CS agent may have given you a confused response, but it doesn't sound like you've been short changed (yet). Fingers crossed, but I think you'll just need to wait it out