Hi Kathy, My name is ***** ***** I'll be answering your question today.
What game are you experiencing trouble with?
ok. I was just going to ask if you have verified your account information.
if you are not able to update it. you can remove the app from your phone and then reload it from the app store. This will reset the account.
Keep in mind, some apps keep game progress based on your Facebook account or your apple ID. depending on how the game authenticates
Here is a how-to for updating your account information: http://www.bigfishgames.com/blog/ios-iphone-ipad-ipod-help-faq-and-technical-support/#target_8
Once you associate it with your current account, you should be able to use in-app purchases again.
I hope this answers your question. Please be sure to rate my service if you are satisfied that I answered it to your satisfaction (3 stars or better). If you have additional questions on this matter, please reply back.