Issues with experience letter

I absconded my organization a few years ago due to a life event i.e. my marriage. To give you a back story three months ago me and a few other employees were chosen to get trained abroad and relocate to a new city to transition new business. During this time my partner proposed and set a date to get married , since we belong to different religions we planned a court marriage . I informed my manager two months ago that I would need leaves for 4 days to prepare and complete the formalities and any get together post marriage. He stated not to talk about to it HR or the upper management since we were in the middle of a new process being transitioned and I was heading it. I waited until the last few weeks to approve when that didn't happen I emailed the directors and HR informing the same, but didn't receive any reply from them. The night before I was to fly for my appointment, he denied my leaves stating I need to reschedule my marriage. This ticked me off and I absconded. However now the settlements team is not releasing my experience letter until I pay the amount incurred by the company for my trip and stay and any other expenses they incurred . Also there was no official conversation about liabilities if any in case I decided to quit before a certain time during the transition. I have spoken to HR and settlements and for the past two years struggling to get my experience letter that's accounts for 10 years of my time with this organisation.