Cell C is bankrupting my business

I would like to express my utmost disappointment in Cell C which is resulting in me not being able to get any new work as clients can't call me on my business phone. I bought a business and got the phone with the business which is on the previous owners name.

I have thousands of rands worth of adverts running and they all have the number for which the sim card doesn't work and Cell C doesn't want to do a sim swap and change the sim card to my name even after the previous owner went into Cell C himself to get this sorted.

This has been going on since last week Friday and I have already lost thousands of rands income, this is seriously hurting my business.

Should this not be resolved I will have no other option but to pursue legally as I will already not be able to pay all my expenses.