You're locked in for the year. I did the same thing back in May. About a month before your anniversary date, you should receive a mailer and/or email from your supplier regarding renewing. While they'll likely charge somewhat more, it may still beat PPL's proposed rate.

My hunch is PPL itself is purposedly raising their rate excessively to shift more people to shop 3rd party suppliers they (and/or insiders) own an interest in. Would like to see this investigated. PA is among the most energy diverse. Such large increases don't make sense to me unless there's corruption involved.