Refusion of my Visa application to Canada

Hello,
I'd like to ask my visa application refusal. I applied 2 times for my visa to visit to my brother in Vancouver. I applied together with my mum coz I have to accompany  her due to her inconvenient movement. The first time was refused because we didn't submit complete and relevant documents. For 2nd attempt, only my mum's visa has been approved but mine has been refused again even I have submitted full documents. The reasons  why refusion are purpose of visit, current employment and property assets and financial statement. But I did mention all these factors.
My question is why the embassy didn't accept my application. My mum is unable to travel alone without anyone help. I spent my money for 2 times application US$400.
May I know if anyone has encountered this experience like me? Please advise.

Thank you.

It might be best to appeal their decision directly or at least, get in contact with the consulate for a full explanation.

Thank you very much, Tim. I've emailed to the embassy to review thoroughly my documents and explained in details about their requirements. Finally, as you said migration Manager accepted my appeal letter and issued to me my visa and allowed me to visit to Canada with my mum together. Needless to say, I am over the moon as soon as received this issue.
Cheers!