Truth is priceless, lies are free. The N.T. loves to paint Jews as nasty, and poor unsuspecting readers buy it without a second thought.
According to Rambam, the mitzvot of the Jubilee came to an end when the tribes began to become exiled, because of the pasuk written on the Liberty Bell (Leviticus 25:10):
You shall make the fiftieth year holy. You shall proclaim freedom throughout the land for all its inhabitants. It shall be a jubilee for you.
Once the the tribes of Reuven and Gad and half the tribe of Menasheh were exiled, the land no longer had "all its inhabitants". This is when the mitzvot of Jubilee ceased (may it be reinstituted after the gathering of all the exiled immediately!).
Interestingly, the point the poster in your quote is making is actually a law of Shmita (Sabbatical Year), not Yovel (Jubilee). This is when all are bound to forgive their debts, and it happens every 7 years, not every 50.
Hillel did indeed institute the concept of a pruzbul - a legal document that prevents the cancellation of debts during Shmita. I am happy to quote wikipedia in this case, given we are answering for the nonsense of conspiratorial Christians, who might be surprised to find that a source that isn't "controlled by the elders of zion" that disagrees with them:
The Torah mandates a Sabbatical year, Shmita, every seventh year (not to be confused with the Jubilee, which is the year following seven cycles of Shmita).1 Among other things, the departure of the Sabbatical year cancels all debts. This is one of the many laws in the Torah meant to protect the poor and disadvantaged, affording them a chance to escape from eternal debt.
Conversely, the law harmed the lenders who would never be reimbursed once the Sabbatical year ended to remit all debts. The wealthy refused to loan money during the latter years of the seven-year cycle, refusing the poor even a temporary opportunity to make ends meet.
The rabbis of the time found the state of affairs to be both a major challenge to the status quo and a violation of numerous mitzvot, Torah commandments, that require magnanimity to the poor, including one within the aforementioned passage in Deuteronomy.3 The rabbis, under the suggestion of Hillel the Elder, created a loophole in Jewish law, in which a legal document would accompany the interest-free loans (charging interest to fellow Jews is forbidden in the Torah) issued by individuals that stated that the loans were to be transferred to the courts as the law of remission does not apply to loans within the public domain. This groundbreaking institution benefited both borrower and lender; because lenders knew their money was safe even following the Sabbatical year, they were likely to loan to the poor.
So basically, the pruzbul was instituted by Hillel in order to help the poor, not hinder them. The Torah and the Rabbis were very conscious of the reality of human nature, and realised that the people were no longer on the level where they could keep this mitzva properly in a way that does what it was intended to do - assist the poor. People were refusing to lend because they were afraid they would just have to wipe it off, especially if it was close to the next Shmita. So the pruzbul became the solution.
I just want to add something further here, if I may. Part of the lie is based on a falsehood - lending money to the poor is a means to control and oppress them. In fact, the Torah makes it a mitzva to lend money to the poor because, well, it is a MITZVA (a dignified way to get someone back on his feet in a time of need, that is sustainable). The Sefer HaChinuch (link above) explains how it is an even greater mitzva than charity (and, believe it or not, not because we side with the rich over the poor! Check it out, and note how there is no mitzva to lend money to the rich, so clearly this is for the benefit of the poor only).
The Rabbis obligated rich people to lend to the poor, and kept them in check - they are not allowed to insist on it being paid back if they know the borrower can't, and many other wonderous details about how to be a lender in the most moral way possible. The poor should thank God every day that Jesus didn't get his way on this... If people were declining to load back then, we can only imagine what would be nowadays...
Also, the pruzbul didn't "get rid" of the lending laws. On the contrary, the pruzbul is optional, and many Jews today decline to get one, or get one simply as a precaution against accidentally claiming a debt that is halachically written off, but generally let go of the debt unofficially anyway.