I submitted an assignment in pdf file and it was cancelled but I didn't receive a clear response as to why. Is it the amount?

I submitted an assignment in pdf file and it was cancelled but I didn't receive a clear response as to why. Is it the amount? if so I can increase it. Is it the time frame provided to complete the assignment if so I can extend it an additional 2 weeks. I just really need help with it and looking for some guidence.Thank You, Johane