“The Debt Collector” is a rigidly, laughably formulaic martial arts thriller that takes forever and a day to tick off the checklist of ingredients of that formula.

The plot of this Thai tale is so moldy, with one mandatory waypoint or plot point following another, it’s sprouted its own rainforest.

But hey, the fights are OK and the chases pass muster. More or less.

Nadec Kugimiya of the “Death Whisperer” movies is our anti-hero, Num. We meet him as he’s shooting and slapping, beating and butchering a “deadbeat” debtor in hock to Num’s boss. Riddling the debtor with bullets isn’t just a bad business model. It lands him in prison.

But hard-hearted and handsome Num underwent a Buddhist spiritual conversion during his decade in The Joint. His priest/monk (Paphon Jirahitaphat) tells him “You are released from your suffering,” when he gets out. It’s implied that he’s released from the need to make others suffer, too.

But that delivery job he takes puts him in contact with street vendor Granny Lek (Kunkanich Khumkrong) and her tiny granddaughter (Ploypaphas Fonkaewsiwaporn). Num isn’t likely to stand by while her cart and business is repeatedly trashed by loan shark “debt collectors” thugs just like he used to be.

Being newly passive and “enlightened,” he pays Granny’s way out of the violence he sees them facing.

“May Buddha protect a good man like you.”

The problem is, that was just one payment. Everybody at the bottom of the social ladder seems in hock to this pale, thin punk Po (Daou Pittaya Saechua) with the hair-trigger temper.

As Num is forced to intervene, that puts him in Po’s sights, in the crosshairs of Po’s hulkish enforcer (Jack Jonathan Holman), on the radar of corrupt cops (Chaiwat Thongsaeng) and crime boss Madame Pim (Nualprang Trichit), who runs things in the city underworld.

There’s sure to be trouble.

The fist, firearm and knife fights are good enough in that “We’ve all seen better” sense. The same goes for the chases — adequate, nothing special.

But it’s the hoary plot that really grates. Our hero grew up in an orphanage, and guess who was his best bud there? Guess how the Dragon Lady crime boss figures into the hero and the villains’ histories?

Don’t bother guessing what happens to the people Num takes an interest in or advice from. Don’t expect no one to say “Using violence is never the answer” because somebody, sure as shooting, will.

Director and co-writer Surapong Ploensang (“Cracked” was his) and his co-writers pile on the cliches — a little terminal illness here, a few past victims haunting someone there — in this not-so-epic epic.

Pacing has been the downfall of many a thriller, and this 80 minute movie packed in a 132 minute package underscores that. If your movie’s slow enough, there’s more time for screenwriting mischief, more minutes allowed for all these superfluous cliches and tropes.

Cut this calamity to the bone and it might go down easier, and it certainly would pass by faster.

Rating: TV-MA, graphic violence, profanity

Cast: Nadech Kugimiya, Daou Pittaya Saechua,
Nualprang Trichit, Paphon Jirahitaphat, Jack Jonathan Holman and Chaiwat Thongsaeng

Credits: Directed by Surapong Ploensang, scripted by Ornusa Dasawaia Pun Homcheon and Surapong Ploensang. A Netflix release.

Running time: 2:12