I had this problem with my Paypal account the other day. Turned out the system automatically blocked my account because the steam postal address did not match the Paypal address. You've done the right thing--contact support, they will probably ask for your address etc. and then unlock your account. My wait times were around 8 and 14 hours, probably more. Still waiting for a reply after I tried another order, to make sure my account is working okay, no reply and it's coming up on 48hrs now. Patience is a massive virtue... There is a long related thread on the Steam forums (help section), and at least one person has confirmed they are not honoring sale prices even if you miss them because of the payment system. Good luck!