Hi John,
Thanks for contacting us and I’m sorry to hear you’ve experienced difficulties.
I strongly suspect the second point – the fact that stock levels are not decreasing – is a result of the first issue (the fact that something is going wrong during the payment process).
Although Event Tickets Plus can integrate with WooCommerce, it generally does not involve itself or interfere with the order process. So, if something is going wrong during the payment process, it’s highly likely that the problem sits at the WooCommerce level (or is an issue with the payment provider themselves, or the payment gateway plugin).
If you want to be doubly sure about this you could create a new product (ie, not a ticket but a regular product) and perform a test transaction. Note that for such a test the product would be ‘simple’ and of the virtual type – you’d also want to set the inventory. In essence, if you can replicate the same problem with the test product, then it is not actually a ticket-specific problem.
The next step from there would be to seek support from the Woo team, particularly if this is the gateway you are using (which I believe they support).