Clearo coils don't last

Hi, I've been using the twisp clearo for more than a year now. At first I was very happy with your product, but now I find that the twisp coils don't last anymore. I bought a packet of 5 and it lasted a month where before it lasted up to 3 months. When I enquire at the twisp kiosk, they tell me about the change of supplier and I'm sure it's a problem then. I referred 4 people to buy and use your product but none of us are happy using it anymore. I use the twisp juice but it costs me more in buying coils. I bought a single coil on Saturday and it never worked from the start! Can you supply us with decent quality coil please! They are not cheap!