Unhappy customer

I went to the gateway store about 3 weeks ago and the lady at the store at that time said I should come in on the 6th of July 2021 which is today to cancel my contract as it is coming to an end when I get to the store today I'm told I have to give 30 days notice and I will be billed in August last but the consultant the first time I spoke to didn't mention anything of this sort, this is really unacceptable as we are living in tough times it's not easy for people to just pay when they feel they won't make it,really unhappy with telkom been a client so long....