Poor customer service

Good day,

I recently opened an RCS account and the process was relatively easy. However, when I need to contact RCS, the call centre unable to handle the call volumes as every time I try to phone it takes more than 20 minutes and even after that amount of time, no one answers. I recently made my first purchase which was for an amount of R4645-00 at Tyres and More/TWT Lynnwood on the 11th of November 2019. As advertised on the TWT website it states that for your first purchase of R1500 or more you get a R500 discount (valid until 31 December 2019) and the TWT Lynnwood store told us that it will be deducted on RCS’s side, however the R500 has still not been deducted from the original purchase amount when I look at my available balance and the transactions on my statement. Please could you assist me with this. I have resorted to sending emails (I have sent emails twice), which are going unanswered and even the contact us form on the RCS website (which I sent three times) but I am still waiting for a response. Please could you assist me with this.