Wise person collecting bill is about to get refunds (7)
I believe the answer is:
rebates
'refunds' is the definition.
(rebate is a kind of refund)
'wise person collecting bill is about' is the wordplay.
'wise person' becomes 'seer' (I've seen this before).
'collecting' is an insertion indicator.
'bill' becomes 'tab' (a tab is a bill at a bar).
'is about' says the letters should be written in reverse.
'seer' enclosing 'tab' is 'setaber'.
'setaber' written backwards gives 'REBATES'.
'to get' acts as a link.
(Other definitions for rebates that I've seen before include "Refunds -- discounts" , "Retrospective discounts" , "enclosure?" , "Partial refunds, reductions in payments" , "Refunds of some of the amounts paid" .)