Most likely never got the refitting and modernization let alone just making them safely seaworthy and ended up getting scrapped. That was right at the time when the EN was not really in a good place as far as being a well equipped and capable navy, certainly nothing like it is today and those subs were cold war era built (27 total were built the last ones in 1978) and most likely needed a lot of refitting that it wasn't worth it and never ended up happening."In 1989 Egypt purchased two Oberon-class submarines from Britain. These submarines would require refitting and modernization before entering Egyptian service."
What has happened to these?
Either that or they did serve a couple of years at the most and then were junked. But those were pretty large submarines looking at the first pic.