Poor service

I am so disappointed and frustrated with RCS as I had the most horrible experience this weekend. I went grocery shopping at shoprite and went over my limit with a R500 and the transaction was declined,I reduced the groceries to my credit limit and it was still declined.I left the groceries and left the shop, when I contacted RCS - long story short they advised something about a ***** alert,they can authorised for the transaction to through after Identifying and verification process.I then used the card and still had R500 available on my credit limit, I went to Pick n pay that same day and made a purchase of R169.00 which was also declined, furious with the horrible experience once again I contacted them and was told the same story of ***** alert, they transferred me to the ***** department again but the call got disconnected and I just gave up calling back again as I has already used up alot of my airtime just calling them for the day. I am so frustrated that I am considering closing my account with RCS.