Facts:

On 25/4/18, the Respondent, Nigeria Export-Import Bank, which was the Plaintiff at the Federal High Court (the lower Court), filed a Writ of Summons on the Undefended List, by which the Respondent claimed the sum of ₦147,465,753.42 from the Appellants, the same being an outstanding debt plus accrued interest on a loan facility as at 22/11/2017. The Respondent also claimed interest on the said sum at the rate of 10% from 22/11/2017 till judgment, and thereafter, at the rate of 10% per annum until the final liquidation of the judgment sum. However, the Appellants who were the Defendants at the lower Court filed a Notice of Preliminary Objection in which they challenged the exercise of the jurisdiction of that Court in the matter on two premises, namely: (1) that the matter before the lower Court was an abuse of Court process and (2) that there was no valid Writ of Summons before the lower Court as the suit was commenced with the private correspondence paper of the Respondent’s law firm and not the prescribed forms in the Rules of the lower Court. After hearing arguments on the Preliminary Objection, the learned trial judge overruled the Preliminary Objection for lacking in merit and struck same out.
Dissatisfied with the decision of the lower Court, the Appellant appealed to the Court of Appeal.