Vodacom account is a mess

Since we upgraded in June 2020, our account has been a mess, we have contacted Vodacom far too many times to try and sort this out, we have asked a manager to contact us, to no avail. All we keep getting is a recorded voice message, telling us we owe them money and we don't!! We have spoken to so many different people to try and sort it and we get shunted from department to department, but nobody can sort it out, we even did an account recon and sent it through to them...., NO RESPONSE!!