Contract SIM card error

We have a contract with Cell C, 3 days ago their SIM card showed an error: network failed. Today I called the customer care from a landline because this is the Only Cell C SIM we have, I spoke to Cebile who told me I need to call when I'm with my husband. I even told her that I just need to know what the problem is with my SIM card but she said she won't check until I call with my husband. I spoke to her supervisor Lungani who could not assist. He told me to buy a new cell c SIM so that we can call again. At Ulundi we no longer have a cell c store but this supervisor told me we can go any other branch. When my husband took this contract for we were together at the store and we did mention that I'm the one who'll use this SIM.