I thought they have always charged taxes on PayGo, or a least since I opened an account. Mine=$10+1.28Tax
They have always charged tax on paygo. Yours is actually very low. -in Feb my pay go $10 top up had $1.44 of tax on it! My state has a flat 911 charge. The only thing they didn't charge tax on was data/text only plans.
oh, originally had free $10 top-up, I think.