Change the oauth redirect url

We need to change the oauth redirect url of our plugin, but it has been impossible to get it changed on Squarespace's end. What we have tried so far:

- fill the oauth form again https://partner.squarespace.com/oauth-form, but we don't get any response
- contact the live chat support https://support.squarespace.com/hc/en-us, but they ask us to fill the form

so last resort is the public forum. Anyone knows how to get a response from Squarespace dev team? It's a very simple change on their side but we have been blocked for months.