Learn to Read!
If there’s a “Please wait to be seated” sign, you should wait until someone guides you to a seat. If you just barge into the restaurant and take the nearest empty table, you’re not going to get the kind of service you wanted. The OP will make sure of that.
Whenever someone sits down by themselves and makes a fuss about not receiving service, the OP would “apologize” and remind them that the person who seated them will come back to help them soon. Imagine the confused looks on their faces when the realization finally hits them.