Telephone support works for only a limited range of problems. The solution usually is to go back to your vendor - or with Costco (and perhaps with other chains), to a local store. Problem solving usually requires changing something in the aids, and that requires hands-on by Costco or their supplier. I’ve always found Costcos wherever I find myself to be very responsive to problems over my almost 14 years using their HAs; the service I’ve had is the same in Boston, Springfield (MA), CT that I get at my home Costco in IL…
If you want disposables, I would not go with 312s; they don’t last long enough. I initially bought Jabra EP10s as rechargeable units. Then, on a trip, I misplaced my recharger and had to go without the aids for some hours until I reminded myself that all my travel bags and the charger were black and looked again and found the charger.
It would have been easy to buy a new charger, but I’d have had to wait 2 weeks from either Costco or a local practice.
I went to EP10s with the 13 battery and get 8-14 days with Kirkland batteries. In retrospect, the rechargeables were fine, able to go 14-16 hours with something left over in the batteries, but … although I have difficulty replacing the 13s, I think I’m better off with them than I would be with rechargeables.
I like the 9040s a little better than the EP 10s, but ReSound/Jabra sells the Multi-Mic, which is immensely useful in meetings, restaurants, etc., so I stayed with the 10s. The Multi Mic probably is not as good as the Roger mics, but it’s way less costly. I’ve never tried the EP20s, but my guess is they’re a step up from the 10s, and it could easily be better than the 9040s, being newer. But you need to satidy your ears, not mine. 