Interest rate on loan

May be harassment is wrong, but he can initiate a civil action to recover the loan advanced to you.

It appears that the loan is barred by limitation..

You do not respond or acknowledge the loan even if he issues a legal notice.

Let him go to court, the court will not entertain a time barred suit for recovery of money  which cannot enable him to recover the loan amount 

The lender has a right to recover the loan / outstanding amount if it is well within law, however, being 4.6 years old, it is barred by limitation.

It is better to settle the dispute amicably.

If you have not paid the loan amount and agreed to pay interest 2% then you have to pay; though he was supposed to claim money under Promissory note in three (3 ) years , If he did not asked for any money or  you paid part of money then the date will start from the part payment, otherwise three years for PN to be valid

You have to pay money return back with amicable solution. Otherwise lender file a criminal complaint with police or file a criminal suit in the court of law as follows. 

File a criminal suit:

The borrower must show that the person borrowed the money and committed a criminal act of breach of trust. He can therefore file a lawsuit under Section 420 of the IPC because the person he had to lend them money to defrauded him, as well as under Section 406 of the IPC for Criminal Breach. If the court finds the defendant guilty, he will be sentenced to prison and will have to pay back the money he borrowed. Cases filed under this clause typically take the court a considerable time to resolve.

On the question of limitation, the   period   from 15.03.2020 till 28.02.2022  stands excluded for the purposes of limitation as may be prescribed under any   general or special laws in respect of all judicial or quasijudicial proceedings as directed by the Apex Court by the Order dated 10th January 2022.