Application declined due to " poor credit rating"

I have a current data contract with vodacom. I wanted a second one. My online application was declined due to bad credit rating. Impossible to find out through the call center what the problem is or dispute it. I have done online checks at different sites and have an excellent credit rating! Something doesn't make sense. Nobody is willing to assist or explain why it was declined. They just keep on saying " bad credit rating". And put the phone down in your ear. You cannot speak to anyone else that can assist. I wouldnt have app**** if I didnt need it! Pathetic unhelpful service. And with the country being in lockdown state we have no other available options...I am so disappointed in how vodacom treats it's customers