I haven't contacted the new line for uk dexcom. However, the sensors are only supposed to be worn for 7 days (& I think they might only be under warranty for 5 - that is coming out of my unreliable memory tho...) so there is absolutely no way they would replace a sensor if you had had it in for more than 7 days. However, if you had problems or faults in the first week (? 5 days) I'm sure that would be replaced.
They've moved to 7 days now. And you're correct about beyond 7 days.
Sent from my iPhone using Tapatalk