Sorry to hear that your issue is taking so long to address.
Do you have a ticket number for this issue, please?
In general, it’s not so much support as the development team that takes time to resolve issues like this. The dev team has a backlog of items to fix, usually in the range of 30-50 issues.
Each item is prioritised based on business impact; for example, a broken checkout or payment gateway that prevents orders from being placed is given highest priority. The priority of an item depends also on how many users are affected, i.e., the number of people using the feature.
I appreciate that this is obviously negatively impacting your business, and if you can supply the ticket number, I’d be happy to give you an update.