Write to the head office, send the letter by registered post, keep a copy and the receipt.
Permanent TSBHead Office
56-59 St. Stephen's Green
Dublin 2
I have no experience with writing one of these letters, but just state all the facts;
You account number,
when you fixed,
what your contact says,
what was/wasn't said (no advisement, banks do have a legal duty to work in your best interest),
what has happened now,
what should have happened.
keep it professional, dont debate the issue. state in the first and last line that you require a FINAL RESPONSE on this issue.
best of luck