Rasheed, one thing is obvious, ligation was unsuccessful. Does your gene of interest have these 2 restriction sites? Did you first run the digested products on a gel to make sure you have the right bands of interest, cut and purified using gel purification method? Also if you need to do colony PCR first, the best set of primers would be the inner primers which you used to amplify your gene of interest. And lastly. for double digest with these restriction enzymes, i will suggest you digest your products first with HindIII, run on gel, cut out right bands and purify, then fix the second digestion with SnaBI and also gel purify before fixing your ligation reaction. It is also advisable to do a negative-control plate, this will tell you if your ligation was successful or not as there will be fewer or no colonies in your negative plate when compared to your positive. Hope these tips will be helpful to you.