Sim swap ***** results in R22000 loss

On 9 March 2021, a ********** sim swap was done on my sim card. This sim swap led to two transactions amounting to a total of R22149.00 from my credit card. The transactions were authorised by the bank through the use of two one-time pin numbers that were sent to **********ly altered sim card via SMS. After investigating (numerous visits to MTN branches and phone calls to Customer Services) I discovered that the sim swap had taken place at Incredible Connection at the Eastgate Shopping Mall in Gauteng at 8.30 at night - I live in Pietermaritzburg! Although I reported this ***** to MTN on 8th April, the investigation still has not been resolved (by 17th May). I am tired of waiting to hear from them now.