FNB not willing to transfer discovery card

Good day, <br> <br> i have a Discovery Credit Card which is issued from FNB. over the past few months i have not used the Discovery card due to no ebucks being earned. <br> <br> i went into the bank on 25 September 2015 and requested if they can swop the discovery card for a FNB gold card. <br> <br> the branch manager and call centre indicated that this was not possible and that an application had to be made for a new card. <br> <br> i am now retired and earn some rental income, yet in order to get the new card they want a salary slip.<br> <br> this does not make any sense as i currently have a Credit Card via FNB and all i wanted to do was change the card type. i did not request a increase in credit. <br> <br> at the end of the day, i can keep the discovery card open with FNB provided credit but i will not benefit for the ebucks rewards. so i just cant understand why fnb cant issue me a card directly.<br> <br> Please advise if this makes any sense or is this just how FNB operates. An emailed response is preferred.