Charged for seat assignment but did not assign seats

They charged me around $45 for seat reservation and all it end up was I could able to select the seat while purchasing the tickets through cheapoair and I received an email saying "your ticket was booked however your seat selection is Cheapoair submitted your seat request to airlines but we cannot confirm on the seat unless they do". And I did web check in and got some random seats. It is not worth paying an extra bucks for seat reservation in cheapoair. It is all same either you select the seat or you do not.