Impossible illusion? Prank with no credit, I repeatedly fancy (6,4-5)

I believe the answer is:

indian rope-trick

I'm a little stuck... Click here to teach me more about this clue!

'impossible illusion?' is the definition.
'indian rope trick' can be an answer for 'illusion?' (I've seen this before). I am unsure of the 'impossible' bit.

'prank with no credit i repeatedly fancy' is the wordplay.
'i repeatedly' can mean two substitutions for 'i'.
'with' says to put letters next to each other.
'fancy' indicates an anagram.
'no'+'credit'+'i'+'i'='nocreditii'
'prank' after 'nocreditii' is 'nocreditiiprank'.
'nocreditiiprank' with letters rearranged gives 'INDIAN ROPE-TRICK'.

Can you help me to learn more?

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app