Insist on getting the payment absolutely correct (5)
I believe the answer is:
exact
This might be a double definition.
'insist on' is the first definition.
(I've seen this before)
'absolutely correct' is the second definition.
(exactly right)
'getting the payment' is the link.
I am not very happy about this link. Some or all of it may belong to one of the definitions.
Can you help me to learn more?
(Other definitions for exact that I've seen before include "Precise; extort" , "Explicit" , "Precisely correct" , "Not approximate; inflict (revenge) on someone" , "Precise, accurate" .)