Spark
is the only person who could refund or adjust your price.
What most times happens is you pay the $350 for your Dealer membership.
Then your existing $60 Platinum membership fee gets prorated into extending your new Dealer 1 year membership.
You joined yesterday, so 2 days of the $60 is used. Doing the math comes out to approximately 95.8 cents a day for your Dealer membership. So take the $60 - 2 days comes out to 33 cents/day used up.
You should get an approximate 61.5 days of extended Dealer membership.
This is assuming you were to upgrade today. However the math calculations remain constant, just divide, multiply, and add.
However as I said, Spark can make a final monetary adjustment for you.