Rights to a working oven??

Moved in in November.  LL said they would send someone to fix the bent oven door which is so warped you can see the element when you look down.  After cooking in the oven I realized that it burns everything to a crisp and leaves the middle raw.  "Vendor" came out to fix door and failed to do so.  When I asked if that meant I would get another oven, I was told that it was a builders grade appliance and thats just how these things were so no.  I can not use the oven as beyond it burning/not cooking EVERYTHING, I feel it is a safety hazard to my children who could easily stick their hand into the oven or even get burnt from the air escaping.  And it also makes most of the metal on the stove and door hot enough to burn you if you touch it.  Normally I would keep complaining until something was done but they always send out the same vendor for appliance repairs (and he still says the LL won't replace each time i see him for other things)... I am at my wits end and ready to be done with this place.  I would have moved long before now and just forget about the $700 I paid for a deposit  but I thought I could deal with it so that I could get the money back.  After 8 months, I can honestly say i really dont even care about the money, yes its that bad of an inconvience not having an oven! Im the family cake decorator and can no longer do that at my own home.  I also have to resort to cooking everything on the stove for my family of 5.  Don't I have some sort of rights to a working oven???