The annoying thing is, you put in a cash back request and they simply delete it and give you a generic answer.
I am going to the commerce commission as shopback has acknowledged multiple times they are aware with temu issue but they continue to advertise it leading to sale under false pretenses, I'm not 100% sure what we can get them on yet but I'm not happy, its damaging their brand and I'm also wanting to make a class action suit, I have reached out to some legal representation. If you would be interested in joining we will need to have proof you have already tried to request missing cash back, plus all the details of the cash back.
Are you interested
While this doesn't help you in any way, note that Temu affiliate tracking tech is known to be iffy and many users have reported not receiving cashbacks while shopping on Temu (regardless of which cashback provider they go with).
On Australia we've seen complaints from Cashrewards users and on Reddit's Rakuten USA similar complaints exist.
I personally don't shop on Temu anymore as I've found most of their items really garbage (and I hate the minimum spend threshold), but if you do want the best discounts on Temu, it's generally better to just use the first-time customer coupons for an upfront discount rather than a cashback for an "eventual" discount. You can usually find such coupons using Coupon aggregator sites, and Micrsoft's Edge browser also has a coupon finding feature too.
If you are having a 100% failure rate with Temu cashbacks then you might want to look into your browser settings, you may have an extension enabled that interferes with tracking (e.g Adblock, extensions that inject their own affiliate links, or other privacy focused extensions) or you might have used coupons that aren't approved by the cashback provider.