How long is reasonable to wait for the Trial App functionality to be repaired ?

I have been successfully using the Garmin AppTrial functionality on my app for several years now to ensure users who want to use the app for extended periods are required to pay for it. Back in February this year, Garmin broke the functionality when they upgraded the website. Here we are near enough four months down the track and it's still not fixed. Garmin have acknowledged the problem but otherwise have been completely silent about when or even if it will be fixed.

I am missing out on sales as a result and this is causing reputational damage in the view of some of my customers as the system has remained "broken" for such a long time.

- How long should I wait for Garmin to fix this ?

- Should I just implement my own unlock method instead ? This would cause disruption to the existing customer base who'd all have to transfer across to the new lock/unlock system if they want to upgrade.

- Should I ditch Garmin altogether and concentrate on another platform

Does anyone have any suggestions as to how I get Garmin's attention on this to either get it fixed or to get someone to tell me it won't be fixed so I can make other arrangements.

It is so frustrating developing for this platform at times.

Rick