Ruining my credit!!!!!!!!

I have sent Vodacom so many emails trying to resolve this enormous sum they claim I owe, it’s been over a year now and this is on my credit record. Nobody from this entire company seems to care, I go to the store, they tell me to call. I call they tell me to call the debt collectors and email. This is absurd! A whole year trying to resolve this and nobody can seem to do their job. Someone needs to fix this!