MTN how I am supposed to feed my family!

This morning I woke up to find a debit order of R18500?!! my contract is a limited contract and we use data bundles so our monthly payment is R300 I need to pay my bills as debit orders are going off!! I have tried phoning them , chatting with chat bot etc we did get through to support however I am still awaiting feedback!! MTN this is not right! How am I to feed my family!?