Not receiving contract minutes

In 2016 I signed up for a black Friday deal where I was receiving 50gbs data, 10000 MTN minutes etc. In November 2018 my contract expired. I contacted the ********** 222 number to upgrade my contract where I was offered 40 gigs of data and 500 minutes for R299. Ever since November I have only received more data but no minutes. I phoned the call centre on numerous times, sent numerous emails, logged a query on the website and each time I've been given assurances that my minutes will be loaded or that I am on a 30gb day and 30gb night data only contract. This is not what I signed up for. If you have voice recordings or a signed contract where I agreed to this please share this with me. Alternatively cancel my contract or give me my minutes that I signed up for which I have proof of request in an email to ********** I currently have a data balance of 120gb which I don't use but do not have any minutes. It's costing me extra money having to recharge on my prepaid number. I cannot run a business like this.