Well, not repaying a loan is not dharma.
My grandpa used to tell me the Rajasthani story of "A hair from the Mustache". Once a person came to a money lender and requested a loan of 10,000 bucks. The money lender asked him for surety. The man said I do not have anything else other than this hair from my mustache. The money lender took the hair and paid him 10,000 bucks. A bystander was surprised that the money lender (he thought) was so foolish. So, I will also go and get a loan which I will never repay. The scene was repeated with the new man. Money lender too the hair and looked at it and said" Friend, your hair of the mustache is a bit crooked, give me a straight one. The person said, that is no problem. Here is a second hair from my mustache. The money lender took up a broom and asked the person to immediately leave his shop. He said, if you do not value the hair of your own mustache, then you are not a person worth believing. Moral of the story: A promise is a promise, no playing with it.
Saint Tulsi Das said in his Ramacharitmanas about Lord Rama:
"Raghukul reet sada chali a'i, pran ja'e par vachan no ja'i." (It is a tradition of the Radhu clan, one may loose his life but never renegade on a promise)
Raghu, FYI, is supposed to have told a lion who was killing a cow that it should release the cow, he may have Raghu's body for his meal. Lion agreed and Raghu took the cow to her place and returned to the lion. The lion, then revealed its true form, it was (I think) Dharmaraja Yama.
Charvaks, apparently were no great keepers of their word.