I've checked our records and haven't seen any cases similar to yours. Once a vendor has transactions already, you can view them or the history under the Transaction List tab. Since you're unable to see them, this can be caused by too much cache.
We'll have a few steps to try. Start with logging into your account through a private browser. It's the best place to isolate web issues. These are the shortcut keys:
Google Chrome: press Ctrl + Shift + N
Mozilla Firefox: press Ctrl + Shift + P
Safari: press Command + Shift + N
If you're able to see the transaction history using the private browsing session, go back to your regular browser and clear its cache. It's advisable to delete it periodically. It will prevent and fix web issues.