Reversal of upgrade

On 21 December 2020 I received a call from Cell C to advise me that I can get 5 gigs more data on a Connecta 15gig than on my current Smartdata 10gig for the same price. I accepted the offer & the change was effected. Immediately the next day I received a call from my mother to advise that she has no connectivity & that she cannot call out or send sms'es. I called Cell C several times to confirm what the problem was & was put through to technical support who gave me information to make adjustments on the phone's settings. After several adjustments to the phone's settings & several more calls to Cell C, I gave up & called the retentions department on 084 143 on Saturday 26 December to request that the Connecta 15gig be cancelled & to be put back on the Smartdata 10gig. I was helped by a lady called Lerato who told me she would send the request through to the back office (***) & that I should call back if I do not receive a call by Wednesday the 28th December. As I did not receive a call, I called back Retentions on the 28th December & queried my request with the ref. number supp**** ***). The lady could not find the reference number on the system (even though it was noted correctly as it was send to me via sms) so I had to log the same request again with ***. On the 30th December I followed up again but nothing was actioned yet & I was given another ref number ***. Today the 31st December I followed up again & nothing has been done yet. I am currently at my wits end & it feels like I am hitting my head against a brick wall every time I call & explain & get a new reference number that in the end ends up meaning nothing. So far my mother has been without data for (including today) 10 days!