has become higher and higher than before
This is a very elementary form of word usage and referencing. This is not the way a college graduate would write an academic paper. it is imperative that you learn to use more academic and western ways of delivering your ideas. That means, avoiding such elementary words. It would have been more academic to have referred to "has increased" or "continues to increase over time."
I disagree with this notion for some reasons behind.
This is an empty thesis statement. It is empty because it fails to establish the discussion platforms for the 2 reasoning paragraphs. An effective thesis statement will state the topics that will be discussed in support of your opinion. The sentence should be phrased as "I disagree with this opinion because (reason 1) and (reason 2)." The task requirements will be more than met with such a statement presentation.
the government is the sponsor, not the payer.
Incorrect. The government is the sponsor, hence, the payer. The payments are taken from the collected taxes from the people. These taxes are allocated to government sponsored universities and colleges. The government represents the people, whose taxes go to supporting the studies of their children for free. Therefore, it may be correct that the students payback the tuition fees when they graduate to help those who will also benefit from the subsidized education program. Do you see the error of your argument?