If your PIN or PUK doesn't help then perhaps your phone is locked to another network and needs to be unlocked first before it can be used on 48?
https://community.48.ie/t5/The-Knowledgebase/I-forgot-my-PIN-or-need-my-PUK/ta-p/256
You seem to be using a Samsung phone so maybe this is relevant?
Hope this helps.
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