The heat from our oven has caused significant damage to the laminate coating on a drawer and a cupboard door, is there a way to repair this type of damage or do i just have to replace it?
It may be possible to repair, but depending on the underlying material, I would take different approaches.
If it's particleboard, your best bet is trying to patch it with veneer. You can find sheets (for bigger patches) online, or banding at most big box stores. The main problems here are matching the current laminate and applying the patch so it isn't obvious. Some tips: Make sure the surface is clean and ready to take the patch, and try to make the patch as "un-square" as possible, so it doesn't stand out. Tracing paper and a lot of patience are required.
If it's plywood, I would refinish the cabinet. If the laminate problem is from heat, it's going to occur again after the patch. You can apply the same veneer patch method to plywood (it's easier), but this will likely be a recurring problem and you might look into a different cabinet finish or a higher quality laminate.
Do you have a router? I think a collar and bit from a inlay kit would allow you to cut a patch out of the drawer and a matching patch out of a piece of matching laminate and then you could glue it with contact cement and a roller. Kind of like a dutchman patch.
There is a laminate repair paste that may work. Here is a link to one product called "SeamFil" If the damage is occuring due to heat then this may not be a long term solution.
Because it's such a small patch, I doubt you want to order a whole laminate sheet. See if you can get a sample of white laminate, or else you could possibly use melamine tape, cut it to fit, and iron it on.