Sim swap

I am very disappointed with Cell c sim swap policy. I lost my phone about a month ago, when I tried to do a sim swap telephonically I was asked for at least five numbers I had recently contacted. I cannot remember all five numbers but at least I know a minimum of three which was also approved by their system, but they cannot do the sim swap for me because of the other two which I fail. I then went to a Cell c store at Liberty Promenade for them to do a sim swap for me, I provided my identity card, proof of residency and an affidavit which they did not even require, but they still told me that I need to pass the five numbers. I mean what other security check can I provide for them to help me because having an identity card and proof of residency form the bank is proof enough that I am who I say I am. My life is stuck because I can't even access my emails because I need verification from my number.