This is the first problem I've been aware of with using Paypal on the CHA shop site.
We chose it because it's the internet's most popular and used service for taking credit cards quickly and simply, and doesn't require you to provide your credit card details direct to CH - i.e. only Paypal have them, so you're sharing your details with fewer companies/organisations.
The time saving is significant for orders placed online, avoiding the need to process paperwork coming into the office - with Wendy on her own at the moment, this is all the more relevent. She can print out receipts/invoices for people, and just package and send out what people have ordered.
Re. your problem - as suggested previously, logging on to your paypal account will then enable you to change your card details. Here's how:-
1. Go to
http://www.paypal.com, and login (I'm assuming you have your username/password, as you got that far before and it told you your card is invalid?)
2. Under the My Account tab at the top, click on Profile.
3. In the middle "Financial Information" section, click on "Credit/Debit Cards" or "Bank Accounts", depending on what you registered with them.
From there, you can "remove" or "Add" cards and details.
Alternatively, on the payment page of the CHA site, once you reach the Paypal login page you can click on "Continue" under the "Don't have a Paypal account?" on the left hand side (under the credit card logos).
This should enable you to enter all your details, without having to have a Paypal account.
If you wish to remove your paypal account completely, you can use the link "Close Account" in the "Profile" section described above.
Sorry you've found this a difficult experience - if you're still struggling with it, then I suggest you continue to use the snail-mail approach to the CHA office. The CHA will also be happy to cater for those not internet-enabled, or who prefer not to submit details online.
Kind regards,
Julian (CHA website designer)