What is the English verb/phrase/expression for cheating customers with an inaccurate scale?

In the town where I live, many street vendors actively cheat customers by using an inaccurate scale. As a result, people receive less than what they ought to.

For example, if you buy five apples, which actually weigh 2 kg on a standard scale, the false readout might show 3 kg or higher. As a result you pay for 3 kg worth of apples, but you get only 2 kg or even less.

It's called "扼称" in my mother tongue, which means "to play trick with a tampered scale to take advantage of customers". An example:

Jack was back home from shopping at the market where he just bought several apples that weighed 3 kg. But when weighing it with his own scale, it showed only 2 kg. Realizing that he had been cheated, he told his brother: "I just got ____ by that sneaky vendor! I'm going after him now."

Is there an idiomatic verb/phrase/expression for this in English? (It doesn't necessarily fit the sentence structure, that's just a suggestion.)

Edit: Someone suggested 'rip off', is that a idiomatic phrase to describe that behavior?

I'm not sure if this is exactly right, but there is the expression "to put your thumb on the scale", meaning that you manually push the scale down while weighing something, to make it seem heavier than it actually is.

The meaning has broadened out from the original "grocer's shop" context to apply to any situation where someone in charge of making a measurement deliberately makes the measurement incorrect, in order to gain some kind of advantage.

http://idioms.thefreedictionary.com/thumb+on+the+scale

• A method of deception or manipulation that creates an unfair advantage for the swindler, likened to a merchant holding a thumb on the scale when weighing goods for sale, therefore increasing the weight and price.
  You have to suspect that the casinos have their thumb on the scale when it comes to the slot machines. There's no way you're getting fair odds.

How about to give "Short measure"?

Not specifically weight, you see the term used for any deliberately fiddled measurement (Volume, weight, length....).

The OED gives a definition 1 as :

An amount, especially of alcohol, less than that which is declared or paid for. ‘coal users in North Yorkshire are being sold short measures’ ‘the most serious crime is short measure on a pint’

Short-change:

verb [ T ] also shortchange

1. COMMERCE to give someone back less money than they are owed when they are buying something from you:

The check-out girl short-changed her.

​ 2. to treat someone unfairly by giving them less than they deserve:

The case alleges that the company shortchanged female employees on opportunities for promotion.

There are a few idioms that talk about this, like putting your thumb on the scale — biasing a measurement or a situation in your favor.

However, since you asked for a single word, then more generally the term for this would be swindling or cheating your customers.

My grandmother warned of being sold "a pound of thumb" when buying five pounds of meat. I watched the butcher carefully and never saw him doing that. Perhaps my grandmother had better eyes than I did.