There's probably people here with way better suggestions than me . . . I'm a pretty new noob too.
But, when I had my first machine, I would get a burnt taste quite a lot and we thought we were getting just pretty bad coils to be honest. They didn't seem to last anywhere near a month and that was with trying to do everything possible to make them last.
I goofed on my latest machine and bought a Delta II Atomizer with a coil that my machine couldn't run and took it into my local vape shop. The concept of a rebuildable coil seemed really scary to me, personally. Now, I'm lucky because i'm married to an electrical engineer so the concept of building a coil once they showed him how was fairly simple. In fact, they just sold us the kit to build it, guided him while we were in the store, and he actually built the one I'm using now.
In the few days we've had the rebuildable, the taste difference is really noticeable. In fact, both he and I swear there will never be a premade coil again on any of our machines.
If you feel like your local vape store is taking advantage of you, I highly suggest that you try another one. Even if you think it's the only one around, do another search. They tend to pop up without a lot of warning and I don't think they are all built equally. While the store near us was nice and helped, they also felt the need to insult my machine that I had just gotten that day for not being "powerful" enough. I think sometimes in our modern world, people can just be rude.
Just my two cents, hope you get it figured out, that burnt taste is the worst.