I understand your point. Maybe it's not "don't have an expiration date". Maybe the problem is making it way too short. They could have also said "we've increased prices since you bought - you have to pay the difference", which I would be fine with. Either way, still bad business practice :)
Yea his website is no longer posting every single day (more like once every week or 2), but there are over 1k articles for you to checkout on the site.
As for improving... just keep studying and keep writing. Handwriting ads as well. Do those 3 things and you'll be fine :)