I just got off the phone with them and only had to wait about 70 minutes, the guy I talked to was very helpful and understanding, he added my two cards into the system successfully but couldnt buy any coins for me. It looks like my subscription will be safe but the Cartel Coin problem had him stumped. He suggested waiting 24 hours or more and trying again, to me this further confirms its a problem deep in their system.
Knowing that its a frustrating issue he gave me 7 free days subscription and 500 free Cartel Coins as compensation.
So although much of their CS comes in for a lot of justifiable flak on these forums (from myself included) I have to semi quote Luke Skywalker by saying "theres still some good in them.."
Yea... no. I called in, after being billed 6 times for failed subscriptions going through and got jack for it. It really depends on who you get, more often than not the CS rep you'll talk to will be 100% useless.