Poorly handled upgrade and complete lack of assistance

Discovery contacted me to encourage me to upgrade my Gold card to Platinum last week. I submitted signed documents to them only to wake up to a nasty surprise on Saturday morning - that they had processed a transfer of my limit onto the new Platinum card, without notifying me. With effect, my purchases were declined due to insufficient funds (embarrassing) and since the Platinum card has not been delivered yet, I have had no access to funds for the last 4 days. I sent them an email complaint on Saturday to which they have not responded. I called the call centre now and was told they cannot help me. 1) Why would you transfer the limit before delivering the new card, 2) Why would you do this on a Friday before the weekend, 3) Why would you not notify your client to avoid this embarrassment, 4) And now you can't help me and I must just sit around waiting for my new card to be delivered. Massive regret in dealing with Discovery.