Google calendar and mail annoyance - where do I complain

I use Gmail and google calendar but only on a full PC can I accept a calendar invite. On both the iPad and the Nexus phone I can see the "invite.ics" attachment but if I try to open it there is nothing there. I can sort of see the iPad but with the Nexus it is three google products that don't work together.

It is quite annoying becuase I will get a calendar request in email on my phone but not be about to actually put it on my calendar unless I open the email on my PC.

Does Google have a complaint site?

The invite is in your Calendar app on your Nexus phone. From there you can accept/decline it.

There is the option to submit a bug report under the gear symbol in gmail (on pc), they'll also take feedback there.