This is probably the reason, yeah. But after searching for email notifications from Betpanda, I only found this:

As you can see, it only talks about the deposit bonus. I definitely did not make a deposit.
Betpanda usually send free spin bonuses when you are newly registered and after you register when you wager every week.
Their VIP rewards revolves on free spin rewards same with their welcome back and exclusive bonus. You should claim them before it expires.
I’m not a regular bettor here but I remember I get most of my rewards in free spin.