Cancelling an upgrade

I got 2 rooters on special in 2017 where the 1 has been giving us a problem and every time we go to the store they would say it's fixed and okay on their system. But when we get home, it wouldn't work. So we decided to just use the Sim card in my neices phone.

So this month I got a calm to upgrade my contract where the consultant guy said to me I can increase my contract from 5G day to 40G. Then I asked him if I can close the 1 rooter and upgrade 1 which is mine that was not giving me a problem. This guy said yes could do so. So we upgraded on the phn and that it would start working within 48hrs and in that 48hrs I must go to the store to cancel the other number and get a multisim which will have to pay R9 extra for monthly. So I took that idea. Next day I went to the store and was told I couldn't cancel the number and that they just upgraded 1 nu ber. That the other one would still continue till the contract is finished. I explained the whole story and they refused tk herar my story. So I asked them to just cancel that upgrade then since I am still within 48hrs od cancellation. They told me I cannot do it as I was told. And that I must call the online people and can't be assisted on store. So I asked them to call the online people for me and they refused and said that they are about to close the store. And it was 16:45. So they send a call back to telkom 4 me.

In a nut shell j m not happy with telkom and want to cancel that upgrade. Please assist me to do so.