Missing Airtime

My contract came to an end on the 11th of March with Autopage, and I asked that this contract be cancelled. Autopage confirmed that I would be transferred to prepaid as of the 14th of March.<br> However, on the 14th of March, I noticed that an airtime balance of approximately R380 no longer exists on my airtime balance, which only reflected R1.64 - efforts to contact Autopage have been unsuccessful.