The problem with short term debt is there's a pattern of people going into debt again, so sometimes the repayments are not taken into account. But it depends on the nature of the debt, the pattern, and which lender you're dealing with.
Did you speak with a mortgage specialist in the bank before you applied, or did you just complete an application and send it in? Sometimes talking it through with an advisor can help things along, where you've an explanation that will help demonstrate affordability. Start there.
After that, I'd suggest contacting a broker in your case, who can help put your application in the best light. There's not much other advice I can give without seeing a lot more information.