What may be the cause of my oven light bulb continually blowing after just a week's worth of use?

Conventional light bulbs have a filament that can easily be ruptured when red hot by mechanical shock waves such as striking the appliance, moving the appliance, or bumping the appliance. Also, there are special "Appliance Bulbs" that are constructed in a way to minimize this effect and also be heat or cold resistant. Always turn the appliance light off when not in use and especially when the appliance is subject to vibration, moving, or other shock waves. Also be sure the light bulbs compartment has a good gasket and glass dome so it's not exposed to excessive heat & grease.

Replacing it with the wrong type of bulb

...a short in the wiring. Have it repaired.