Rubbish you've a right to return! (3)
I believe the answer is:
rot
'rubbish' is the definition.
(both can mean nonsense)
'a right to return' is the wordplay.
'a right' becomes 'r' (common abbreviation).
'return' is a reversal indicator.
'to' in reverse letter order is 'ot'.
'r'+'ot'='ROT'
'you've' is the link.
(Other definitions for rot that I've seen before include "Drivel" , "Decay - nonsense" , "Twaddle" , "'Decay, decompose (3)'" , "Decay, go bad" .)