Contract Cellphones

On the 17 th of May I received a call from an Indian guy who said he was calling from Vodacom around 17:15. He was offering me a discounted contract of 300MB, 50 minutes for calls and 50 SMS. Saying as I am paying for 2cellphones each on R226 so he's giving me a discount on 1 cellphone as a Loyal Vodacom customer due to COVID-19 pandemic. He promised that I'll start paying R189 with no additional amount or any hidden charges. I asked him several times on no extra charges or any hidden charges then he said no extra charges only R189 to be paid on 1of my cellphones. We made an agreement on that I'm going to pay R189 for the other phone and R226 for the second one. They I went to pay my account at Sandton due to the fact that I changed my bank details so I had to go and pay it on cash. After a week Vodacom called me saying I'm owing them R747.Then I called Vodacom Customer service to find out about my errears then they told me I agreed on migration which will add that R189+ R458 for 2 cellphones according to my knowledge my account is not on errears. I believe that the Indian guy is the one who confused my account he never had a proper explanation. I'd like Hello Peter to help me so that Vodacom will fix this thing of me being on errears and I want to go back to my first agreement with them . I cannot afford to pay more that R458. I even reversed my money cos I misunderstand and Vodacom Customer service is not helping me. Thank you