Training Bond Retention Period

Hello. I would like to seek advice regarding the training bond that I signed last March 2016.

It stated that the training is for 1 week and that the Retention Period is 2 years with the amount to be returned as follows:

100% cost = during training (March 2016)
75% cost = within 12 months from the last day of training (March 2016-March 2017)
50% cost = within 18 months from the last day of training (March 2016-September 2017)
None = after the lapse of Retention Period (March 2016-March 2018)

No other penalties indicated for premature termination of contract. It's weird that it was not specified how much I should pay for "within 24 months before the lapse of the Retention Period."

Questions:
1. What financial liability do I have on the 19th up to the 24th months?
2. If I resign this October, can the company still legally hold me due to the "Retention Period" of 2 years?
3. If the answer to #2 is Yes, is there a way to legally get away from the last 6 months of the Retention Period?

Thanks in advance!

Good day!
I would like to seek legal advice. I am a contractual employee in a company for more than 10 years. I have informed my intent to resign effective in a few months. My main issue is that we were asked to sign, along with my colleages who are also contractual employees, a bond stating that for the training we underwent, we have to stay with the company for 2 years. We will be paying an amount if we will be resigning prematurely. I signed the contract against my will. I stayed with this company as a contractual employee because I want to be able to resign freely. These along with other conditions were stated in the contract we signed. Would I be able to resign without paying the bond, that is, will the company have a strong case should they file a case against me given that I am not a regular employee? I don't receive pay slips nor do I have any benefits from the company. I know I can leave anytime but I don't want any legal issue with the company.