Apalling advantage taken of SASSA pensioner

I am writing this review on behlf of my mother. She is a SASA pensioner. She was on a contract to pay R129.00 and receive R 175.00 airtime. Vodacom chaged this this and deducted R 185.00 from her account on 01 July. When she phoned them to querie this, as she cannot afford this, the consultant, Nelson downgraded her contract to R 59.00 per month for R 70.00 airtime she accepted this. She received an SMS today that R185.00 is due on 01 August. She phoned them again, and she was told that that she was upgraded to R185.00. Please help as she cannot afford this. Her phone number is ***