upgrading and forfeiting all airtime on my phone

I went to cell see to upgrade my package, i was on an expensive package and downgraded. when they downgraded they did not explain to me that i will not get all my free minutes, smses and data bundles with the new package. i came home and called the call center only to be informed that i have forfeited everything and no one in store explained that to me. why would i want to lose all the money i have spend for months. they should have explained to me of that fact then i would have not changed to another package. please help with this