I need help. I was weed eating around the chicken coops and the ditch out front of our house and I think I broke my weed eater. The thing is, it is less than 3 weeks old. it is a Murray. We bought it at Walmart and have only used it 3 times! It just cut off and then when I try to pull the cord to crank it, it only comes out a little ways. I think the motor seized up but why? We mixed the gas and oil correctly and have not had any other trouble from it. Should we just take it back? What could cause this to happen? Thanks in advance for any input.