13th Month and Holiday Pay Help/Info Needed

Hi, I work in Horeca and need someone who knows the law and information about 13th month and holiday pay.

I worked in Belgium in 2021 under a student contract not knowing much about it or work life or work laws in belgium and left in October 2021 and then i returned to Belgium in January 2022 back on a student contract. I got a 30 hour contract in May 2022 which i was told was a really good contract. It had a starting date and no end date.

In October i had a disagreement and wasnt enjoying work and was not a good environment to be in. I gave my employmer a 3 month notice period (way more than i had to give). So the notice was to end my contract on the 30h of December.

A few weeks later (2/3 weeks later) on the 12th of November me and the bosses went through my terms to stay and cancel the resignation letter. On the 13th of November at 11:30-11:45am they agreed to my terms. I was delighted and ripped my copy of the notice up infront of them and a fellow chef (who is a withness to the event). Thinking okay I've ripped up mine, surely they have done the same?

Well on Tuesday the 3rd i got a message from one of the bosses saying i had quit in December and i would not get my holiday pay due to quitting in December 2022? Bear in mind the notice to end employment was THE 30TH OF DECEMBER, she told me there was a new contract for me at work to sign. (And the fact the resignation was withdrawn)

This new contract is a "bepaalde durr" (fixed term) contract. It says 1/1/23 to 31/1/23, remembering my contract from May 2022 is a "onbepaalde dur" (indefinite duration). I believe my contract from May 5th 2022 is still LEGALLY s active?

I sat down with the owners yesterday (Friday) and they told me i would not get my 13th month as i had to "start again" and "start again" on this fixed term contract as this was the "law" and what "has to be done legally". They told me they "sent my resignation and there was no way to withdraw it". I am under the impression there is something not right about this whole situation. I worked from May to December on that contract so am i entitled to 7 months of the 13th month?, and I never officially left and don't believe what they are saying. I am yet to sign this "new contract". I think they are trying to get out of paying something.

Finally, throughout the last quarter I asked about the 13th month for weeks and questions and when it would be paid out, I was told, February, i was told, they have sent what they had to to the government and it wasn't up to them. I really need help and advice on the situation and what to do next.

Thank you