This is how I'd imagine the dialogue would go....
Friend: "I'd like to avail of this offer please."
EBS: "Sorry, we don't offer trackers any more."
Friend: "But it doesn't have an expiry date on the letter."
EBS: "Neither does it say anywhere that the offer is available indefinitely."
At this point, your friend has the option to complain to the Financial Services Ombudsman or possibly the Financial Regulator. If not satisfied, s/he can commence legal proceedings against EBS.
Personally I don't think s/he has a hope.