What Do I Do?

Hi All thank you for taking the time to read this.. I bought 2 items from a seller with over 3000 FB Both items were $1.50 each and $2.00 for postage each. In the discricption the seller says he is happy to combine postage. I sent 2 messages for a revised invoice and have heard nothing. Both items could be sent for $1.40 but $4.00 I dont think it is right. Now eBay have sent me 2 Messages to pay for these items and the invoice is still not revised. I only bought these on Thursday night for my grandson so why am I getting these messages 2 days after purchase?

Crowsman