Yesterday, someone topped up my number with a small amount of credit (pay-as-you-go), and activated unlimited monthly mobile data package.

I still have a data plan (prepaid data, postpaid calls and texts) on my main SIM expiring in a week.

I haven’t used any of it, and contacted my carrier’s tech support stating these appeared unexpectedly. Their response was “We would like to inform you that the credit on your phone number was topped up at a point of sale. The unlimited package was later activated at the same point of sale.”
And? Was the tech support person just trying to imply it was likely paid for in cash and I just shouldn’t care because they couldn’t refund it anyway?

Anyway, one annoying thing about this is that it also activated automatic renewal, so if I wasn’t using the number for a few months, I wouldn’t notice my remaining credit automatically draining.
Hell, if I had registered for their online account, it would even possibly pay that directly from my debit card on renewal.