Poor assessment from Sportsmans Warehouse

I am having a problem with my Asics Gt 2000 v13. I bought in July from Sportmans Warehouse. It was giving me soreness in both my knees and right forefoot. I thought it just needed running in so i used it to about 99km. Every run created the same soreness. I have proof of my runs on Garmin. I have had a v13 before this and no issues. i wrote to consumer_za (asics) and they said take it back to sportsmans warehouse. I took it back to Sportsmans and they took about 4 days to assess and came back to me with news that the shoe has no visible signs of degradation or factory fault. I dont think the manager understands that the shoe can be visibly fine but how does one assess what the shoe is doing under load after a few kilometres. I ran in two v11s and two V12s and one V13 prior to this with no issues. I do not have a chronic injury as i am still currently running in an asics gel-Trabuco with no issues. The asics Gel-Trabuco is also a support shoe similar to the GT series. I am not happy with Sportsmans Warehouse assessment as they are merely doing a very superficial check. The customer is then left to do further testing with a specialist like a podiatrist or an orthotist to do further testing on the shoe which i am not prepared to do. It will be cheaper to retire the shoe. Very disappointed with the outcome. Running shoes are not cheap and one needs to be more mindful about which store to buy from in future based on aftersales service.