had a new cut for my 1992 shogun 3. and now the car wont start. ?

Went to have a new key cut for my 1992 shogun auto 3., but they said they couldn't do it. They put my key in a machine but said it was no. Got back to my car and it wont start. It goes to start but sounds like it is backfiring then dies on me. Got a new mot and never had a problem until the key incident. Help.