The first thing to check is to log into BOTH versions of the game (RS3 and OSRS), in case the purchase went to the other version.
The Bonds for each game version are named differently:
RuneScape Bond
Old School Bond
You can check your confirmation message to see which Bond you bought.
If you discover you have bought the wrong Bond, you can message Billing Support and get it swapped. Please follow the instructions on the
Find my Bond
support page.
If there is no confirmation of purchase message on your account, it means either the purchase was not successful or else you bought for another account by mistake.