How can I cancel my Non-B visa without a work permit before applying for a 60-day Covid extension?

Hello ! I had a first non-immigrant B that I got at Bangkok Immigration but the teacher agency didn't manage to get my work permit and it's of course required to renew my visa (long story short, some department wouldn't accept my bachelor degree). I changed my plans and I'm now going to move back to my home country with my wife from the end of March. My question is simple and I couldn't find an answer yet, as I'm going to apply for a 60-day covid extension once my visa is canceled, how could I cancel my non-B visa without holding a work permit? Thank you! :)