Ok, the issue you are having is NOT with SSG but the payment system, the ONLY way around it is for you to contact SSG directly. You can still have them put a VIP purchase through, but you need to contact them via
https://help.standingstonegames.com/hc/en-us in order to get that to happen.
On that link goto the DDO block, third from the top. Click on "See more articles in this category" on the next page on the right hand size you have a "Contact Support" button there. That takes you to "Submit a Request" if you click on the box below its a drop down menu. Select "I am experiencing Purchasing Issues" Its the 3rd option down.
Fill in ALL the details required in there for such and they will get back to you. They will go through talking you through changing your payment details and so forth, this is done within the game in the DDO Store, if you havent found it before its under your username that shows in the top right corner. Check in there to see that you dont have a payment system that is NO longer supported. Many payment systems got removed. If you use Paypal, try removing it and re-adding it. If you use a credit/debit card, check that your credit/debit card is correct and hasnt expired. Also check to see that your card, through a banking app and such, doesnt have a block feature to stop online purchases, if it does then that will stop you purchasing, and before you say that it doesnt, just check with your bank to see, some banks have moved recently into adding such security and never informed their customers clearly enough, aka they buried that detail in a lengthy email of new features. Also try removing and adding the card back into the system.
If none of that works, contact them back on the email they contact you on and the final thing that will need to be done is that YOU give them written permission to charge the card on file, if you have Paypal it is much easier for them to do the payment through than the card. You will be asked to provide personal information with them in order to also do the payment, even if it is going through Paypal.
I actually had to do this when purchasing Fables because the new payment system on the website didnt work. It is the same for ingame stuff because I have also done such in the past when purchasing a gift for a friend.