I agree with Cunliffe.
There are times, though, when the original [past simple] can be used in reported speech.
I would like to give an example from the popular and famous (Raymond Murphy) English Grammar In Use.
Quote
The past simple (did/saw/knew etc) can usually stay the same in reported speech, or you can change it to the past perfect (had done/had seen/had known etc):
direct -
Tom said: �I woke up feeling ill, so I didn �t go to work �.
reported -
Tom said (that) he woke up feeling ill, so he didn �t go to work.
Tom said (that) he had woken up feeling ill, so he hadn �t gone to work.
End quote
I gave this example just to show what the accepted grammar / pattern is for reported speech.
As I said above, Cunliffe �s answer tells you what you need to know.