Hello,
"im not sure if had the Account migrated to microsoft yet since it was originally a mojang account" - you are out of luck completely. Nothing can be done in this case if the account is still with Mojang.
"I also could not find the purchase receipt if anything i probably bought it with a gift card or pay safe card" - also out of luck.
Don't expect any assistance from Minecraft support in this scenario. Your last effort is the ACSR form, which you probably have already filled out, and if not, here's the link - https://account.live.com/acsr