About 6 weeks ago I had a raging toothache and ended up paying 400 pounds for root canal to 1 tooth and it is only half done.The rest is due to be done tomorrow and I have just been told today that the nhs dentist up the road will take me so rest of work will be free.Now I need to cancel with the private dentist and I feel bad but dp says as we can't really afford private I should jump at the chance of free.What do you think?And will the dentist charge me anyway?