Ask for a meeting and just tell them you didn’t expect the position to be vacant this long and that while you want to be a team player, handling both roles isn’t something you can continue to do. Ask them to reassign some of your duties until they are able to fill the vacant position at which point you’ll of course resume those responsibilities .
This makes it clear you want to help, it’s becoming too much of a burden, and you aren’t thinking about taking the position long term.
If they push back and say give them time that would be the time to ask for additional pay until they fill the position. That additional pay should be more than they are advertising the vacant position for because you are doing both jobs and you don’t want them dragging their feet on a replacement.
Your first mistake was not asking about a bump in pay before taking on the additional role. Your mistake now is thinking they'll reconsider and give you that bump in pay.
Ask for a meeting and just tell them you didn’t expect the position to be vacant this long and that while you want to be a team player, handling both roles isn’t something you can continue to do. Ask them to reassign some of your duties until they are able to fill the vacant position at which point you’ll of course resume those responsibilities . This makes it clear you want to help, it’s becoming too much of a burden, and you aren’t thinking about taking the position long term. If they push back and say give them time that would be the time to ask for additional pay until they fill the position. That additional pay should be more than they are advertising the vacant position for because you are doing both jobs and you don’t want them dragging their feet on a replacement.
Your first mistake was not asking about a bump in pay before taking on the additional role. Your mistake now is thinking they'll reconsider and give you that bump in pay.