Wrong contract

On 23/01/2019 I received a call from a sales consultant from FNB Connect regarding a cell phone contract. The consultant took his time to discuss the different contracts on offer. I then agreed to take up a contract for R499 per month. The contract included the following: Huawei P Smart device, 4000 minutes, 2GB of data and 50 sms's. I received my phone and simcard today. I activated the simcard and found that I have 300 minutes, 1.99GB of data and 500 sms's. I called the call centre to advise that there's been a mistake. The call centre agent said that there's nothing that can be done. I requested that he retrieve the telephone recording between the sales consultant and I on 23/01/2019. He said that he's unable to retrieve it.

I would like the person responsible for this to correct their mistake and give me what was agreed upon.