Been round cargo store, and was indebted (8)
I believe the answer is:
beholden
'indebted' is the definition.
(I've seen this in another clue)
'been round cargo store' is the wordplay.
'round' means one lot of letters goes inside another.
'cargo store' becomes 'hold' (I can't justify this - if you can you should believe this answer much more).
'been' enclosing 'hold' is 'BEHOLDEN'.
'and was' is the link.
Can you help me to learn more?
(Other definitions for beholden that I've seen before include "Owing thanks, indebted" , "Owing gratitude (to)" , "Obliged" , "Under an obligation" , "Bound" .)