Can't get hold of anyone

In 24 January I paid R500 via automatic EFT for my cellphone contract. I had forgotten to delete their beneficiary details. Now I can't get hold of anyone at Nashua Mobile and I keep leaving messages, but no one responds. I honestly think this line is not busy and is just a line with a recording. I'm taking legal action regarding this, since it is my money, not Nashua's. There is a word for this, starting and ending with a T. It seems a lot of people on here are having the same problem I'm having with this company.