help!!!

My iphone does not want to charge, I went to the I store where I told the staff member its not charging and I dont know if its my charger or the phone. The member put my phone into a charger and told me its the phone and she cant help me because I didnt purchase it at the istore. I am very dissapointed as this is my only phone, and I cant use it and they are not willing to help. I expected more from such a well known company, known for great service, that I did not experience