False advertising and conflicting information from call centre agents

This year I decided to make the annual payment as advertised in the newsletter DSTV fees 2023 which was emailed to all subscribers. The newsletter states an amount of R10,439 for 12 months if paid before 1 April. I contacted the call centre and was informed that the amount payable is R10,439 for 12 months if I make the payment before 1 April. I double checked that the 12 months can be from 1 April 2023 to 31 March 2024 for that amount and it was confirmed by the agent. At the end of last month, I made the last monthly payment for March and confirmed again with another agent on the DSTV Facebook page that I can make the payment of R10,439 for 12 months starting 1 April as long as the payment is made before end of March. I was told to call again to ask that my subscription be changed to annual before I make the payment. Today I decided to ask an agent on the DSTV Facebook page that my subscription be changed to annual so that I can make the annual payment of R10,439 for April and the 11 months after that. I was informed that the newsletter and all the previous call centre agents I spoke to are wrong. Apparently according to the last call centre agent, I spoke to the amount I was quoted, only applies if the 1st month of the annual subscription is from March so the amount will be R500 more if I want it from April. I tried to explain that all the previous call centre agents I spoke to said it can be from 1 April at that amount but he/she (KM) didn't want to budge or let me speak to someone else. I've given up speaking to their call centre agents now as I feel I'm wasting my time.