I am not able to update transactions and payment of invoices using the android quickbooks mobile app. It keeps saying to contact support for assistance. Kindly assist.

I can see how hard you tried here. No worries, I'll make it up to you to ensure you never have to deal with this again. 

Let's perform some troubleshooting steps to check if this is a mobile application issue where you are unable to update transactions and payment of invoices. Let's start by resetting the data in your mobile app. As long as you’re connected to the Internet, you should be able to update your data. Here’s how to do it on different mobile operating systems:

iOS

1. Go to Menu ☰ and tap Help & Feedback.
2. Tap Refresh Data.
3. Note: A message appears “Caution. If there was a problem getting your latest QuickBooks Online data, you can refresh it now. It may take a few minutes.”
4. Tap Refresh to confirm.

Android

1. Go to Menu ☰ then tap More Options ⋮.
2. Tap Settings then Refresh Data.
3. Tap YES to confirm.

Once done, you can close and reopen the mobile app and update the transactions again. Also, I'd suggest restarting your phone. If you get the same result, you can uninstall and reinstall the app to start a clean slate. The following article contains more information about this: How to download the QuickBooks Online mobile app (Android app).

For more information about the feature available on mobile devices, you can check out this related article: Compare mobile app features.

I've always got your back whenever you have other issues when doing tasks in the mobile app. Drop your reply anytime and I'll get back to you.