Southwest isnt Giving my credit for my Flight what can i do?

I booked a flight Last April 16th for a trip to Vegas for July 21st. I canceled it due to personal issues. The lady gave me a confirmation number and told me i had to book a flight from when i booked this last flight. She said i had to book the flight before April 16th. I call up there to book a flight they tell me i have to use the flight before April 16th arrive and come home.But when i canceled they told me i just had to book it and i wouldnt beable to cancel again. Isnt there like phone logs like when u call they give u the message this phone call will be recorded for quality and training purposes or something. They can look back and see that i was lied to. I Remember asking her to get it verified.