I read your other post that the snake was in your lap sleeping, but I feel I need to comment on your statement that if the boa doesn't calm down in 2 weeks, you'll be unhappy with your purchase.
My new arrivals don't even get handled until they're out of quarantine which could be 3-6 or more months!
During their quarantine period, they get checked on twice per day for a few seconds to see if their cage is dirty, to check for dead mites (thankfully I haven't seen a mite in YEARS), visual inspection for obvious health problems, over-bloating from a meal, etc.
Honestly, that 90-180 day period is usually enough time for that boa to become comfortable with my presence (that's 180-360 exposures to me that were non-confrontational and minimally stressful - plus the few times that I need to actually handle the animal to clean the cage). We're talking very small baby steps here, but it makes the difference. AND, I'm including imports in this.
I'm not saying any of this to be mean. I'm saying it so that hopefully you'll realize that your expectations might be a little unrealistic.
Here's an excerpt from my caresheet on my website:
As mentioned previously, I only handle my boas after the obvious signs of the prior meal have subsided. My method for getting boas out of cages may differ from others, but my boas never bite me so it works for me!
As a rule, I do not handle my boas until they are out of their quarantine period except to remove them to clean. I allow them to acclimate completely to my environment. Despite what you’ll see in classified ads, there is no such thing as a tame boa. There is such thing as a boa that is more, or less inclined to be defensive. Defensive behavior can and does include biting. More importantly, there is such a thing as an acclimated boa, but that acclimation period needs to be reestablished every time there is a drastic change in the life of your boa.
One example I can think of that’s drastic is removing a boa from it’s home that it has acclimated to, stuffing it into a bag, packaging it into a box, sealing it up, shipping it across country on several different flights while going on countless conveyor belts and through numerous hands, drops, and kicks, being stuck on a vibrating delivery truck, bounced around while heading to your door and then handed to you!
If that were me, I’d need some time to get rid of the desire to rip off the face of the next thing that looks at me! So, for the sake of your boa, please allow it to acclimate for a few months before initiating your handling sessions. Remember, we eat 3-5 meals per day; boas eat 3-5 meals in 1-2 months. Their timetable isn’t the same as ours.
Now that your boa has acclimated (generally coincides well with the quarantine period), on to the human introduction!
Some people disagree, but I HIGHLY recommend an appropriately sized snake hook for use with all of your boas. At a minimum, I use it to alert the boa to my presence. A slight touch on the back or side of the boa is sometimes all it takes for me to feel comfortable reaching in and picking them up. Other times, I’ll use the hook to move their head away from the rest of their body while I reach in to pick them up. Still other times, I’ll use the hook to pick up a portion of their body and I’ll use my hand to control the other. Worst case scenario is that I use the hook to move the head away, then I use it to lift a little of the back half of the boa so I can slide my hand underneath, then I’ll use the hook under the front third of the boa to control the rest of its body. In my opinion, the most important thing in handling your boa is consistency and slow deliberate movements that don’t startle them.
I have recently stopped using hooks completely in favor of using puncture resistant gloves from HexArmor. I normally only need one glove as I use it to either put my hand on top of the head of the boa, or as a "shield" to keep them from biting me if they strike. Interestingly, since I began using the gloves, it seems like my boas are less apprehensive about being picked up. Perhaps it's my confidence and lack of hesitation. I've found that once I pick up my boas, I no longer need the glove and free-handle them easily.
I recommend short intervals of handling that gradually increase to your desired length of time and frequency. If you notice behavior from your boa that seems out of the norm like hiding more often and not cruising the cage, or something severe like refusal to eat or regurgitation, cut back or eliminate handling time temporarily.
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What's written above is purely my opinion. In fact, MOST of what you read on the internet is someone's opinion. Don't take it too seriously 
Jonathan Brady
DeviantConstrictors.com
Deviant Constrictors picturetrail
