upgrade!!!! not a contract !!!!!

on the 1st August 2019 i was due for a upgrade and went to my closest MTN store (Hoedspriut, Limpopo) that first weekend. when i arrived at the store, I inform the sales consultation I'm due for a upgrade and selected the packaged i will like. I inform the lady i will like to keep my existing number (due to the fact i use it as my personal number and i don't want to change numbers also) and will like a new sim with the upgrade. Everything went smoothly (I paid R150 for a new contract sim card) I even confirm with the lady this is a upgrade and not a new contact. As i know it will talk up to few months for everything to work out and be normal to what i wanted. I was shocked to find that i got a big debit order(September 2019) from MTN and called the service line to confirm whats going on. They told me i didn't get a upgrade but that the sales consultation opened me a new contract for what i didn't wanted and that i must return to the MTN store (Hoedspriut, Limpopo) where i open it to resolve the problem. When i arrived at the MTN store and explain to them the problem the manager. They told me they cant help me because that I already sign and used the package. 2nd the lady that help had resign from MTN.

I feel it not my fault that sales consultation didn't do their work right and didn't adhere to what i wanted and needed to be done. Now i need to pay for 2 contacts that I didn't wanted and cause a financial burden on me because i only work limited hours and i can't afford to cancel one of those contact a head of time. why would i open a new contract if i'm due for a upgrade in the first place and I'm still waiting to this day for the RM (regional manager) to get back to me because the branch manager said she will forward the problem to the RM and i did leave my contact details be hide.

I just feel sales consultation is a representative of MTN and even if the member resign, MTN is healed responsible for there members mistake because the member reception MTN at that stage i took the contact/upgrade.