Appalling service by vodacom

I app**** for a new contract on the vodacom website, it was a package deal of R279 for two devices hauwei p30 lite. The total amount was R568. After the devices were delivered and activated the activated on the App it reflected an amount of R776. I have been calling vodacom from the 5th of May 2020 to have this sorted out and nothing. For the month of June I was charged R1144. 87, for July it's set at R776. I'm very appalled with the service that I'm getting. I've had a contract with vodacom from 2018 to 2020.i did kot experience this problem. Please contact me asap to fix the mistake that was made by vodacom and has been negatively affecting me. A very irate and dissatisfied customer