Copay balance keep changing back and forth

Here is the situation with my Copay wallet on iPhone right now. I will use all integers to make it easy to comprehend.

For example, my balance was 10 BTC. Then I made a transaction of 3 BTC to an address. The issue starts here.

The transaction shows up and says "sending, a few seconds ago". It keeps "sending" for a while and then disappears on Copay app. Then after a while, it shows up again. It keeps doing this for 2 days without being sent out to the blockchain, I can't find the transaction anywhere using the "receiving address".

I think the balance now is supposed to be 7 BTC (assuming the fee is negligible). However, the app still shows the balance is 10 BTC as the 3 BTC has never been sent out to the network. Is that 3 BTC going around on Copay server?

I understand that I sent out 3, so the "change" 7 will come back to my wallet under another address.
And my balance shows 17 BTC, which includes the original 10 and the "future 7" that will come back after the transaction. This happens when I refresh the balance. Sometimes it shows 10, sometimes shows 17, back and forth all the time I refresh the balance.

Have anyone experienced this? How to fix the problem?

Can I spend the 7 BTC in the meantime? I'm so afraid that if I make another transaction, it will mess up the whole wallet @.@ I'm not too technical to really understand how the code works.

And is there any way to contact Copay support other than GitHub. It seems like they take soooooo looooong to reply to issues over there...

Thank you for any experience sharing!