Charged more than advertised price

I signed up for vodacom fibre in February for a month to month 100/100mb package whilst the fibre rollout in my area was still in progress. At that time the price was around R1049. The price of the same package dropped a few months later to R949 and the fibre went only live after 6 months which was around 20th August. I queried why I am paying more than R949 and was told that it is for "brand new customers only". Am I not a brand new customer? This is the 1st time Im signing up for fibre!! See below quote from email I received:

SR*** - Billing Query Good day Marvin Mouton Apologies for the delay in response. Please note that the price that is found on our website is for brand new fibre customers signing up for fibre only. Please find attached your signed quote with the price agree upon. Regards Clint T Vodacom Fibre to the Home

I have not received any physical contract nor was it attached to the above mail. The Consultant then blatantly closed the ticket without hearing my response.

I am not happy with the way you conduct business. For the price I'm paying now I should at least be upgraded to a 200mb line.

Seeing that I'm on month to month, can I then just downgrade to 100/10mb line for a month and pay the current advertised amount of R899 then upgrade a month later back to 100/100mb for R949?

Why are you guys making things so difficult?