Snapping Elastics

Hey everyone, So i've been having trouble with my elastics, they seem to snap very easily, whether I am talking, yawning or eating. So I called up the orthodontists office and they said that it is pretty much normal to happen with the thinner elastics and won't happen once I get stronger ones. So they asked me if I needed more elastics and I said yes and made mention that I needed another elastics tool because I had lsot my other one at my physical. So the assistant who was on the phone said she would put those in the elastics packets and send them in the mail for me. This was in February, since I wasn't due to go back until March. I recieved them two days later. While I am very far from the Orthodontist's office I am still in the same state.