Receipt may repeatedly frustrate (11)
I believe the answer is:
counterfoil
'receipt' is the definition.
(thesaurus)
'repeatedly frustrate' is the wordplay.
'repeatedly' becomes 'counter' (I can't explain this - if you can you should give a lot more credence to this answer).
'frustrate' becomes 'foil' (synonyms).
'counter'+'foil'='COUNTERFOIL'
'may' acts as a link.
Can you help me to learn more?
(Other definitions for counterfoil that I've seen before include "Chequebook stub" , "in possession of purchaser" , "Record slip for cheque" , "Record kept" , "part of one cheque" .)