Vietnam Visa

I am a Canadian, and applied for and was granted a 'single entry visa to vietnam' GB354576. We will be flying into Hanoi from Hong Kong on Dec 28, 2017, will be cycling to Luang Prabang, Laos and will fly back to Hanoi on Lao Airlines, Jan 15, 2017, before departing for Canada. Should I have applied for the 1 month multiple entry visa? If so, may I get a refund on the original visa application to be used toward the 1 month Multiple Entry visa? Thank you!