To the OP:
Your expereince really did suck, but a lot of it was unavoidable due to the structure of retail electronics sales. Circuit City, CompUSA, and most other retail stores have completly eliminated comision sales positions in their stores to be able to offer lower prices, increase add expenditure, and offer more door busters to get people in the door. While it certainly helps CAGs, the guys on Fatwallet, and others in their ilk, it completly kills customer services, knowledagble help, and customer satisfaction with the expereince.
Stores have also severly cut their operations and managment budgets down to a sliver. Outside of the top managers (GM, Sales Manager, and Operations Manger) most retail store managers make next to nothing which hurts the potential talent pool.
The cuts in operation bugets means fewer CSRs, fewer Cashiers, and fewer warehouse and inventory people (so stock doesn't get put out in a timley manner and finding items is difficult). The ones that are there are underpaid, undertrained, and over worked. By the end of the day it is nearly imposible for them to service each customer in the manner they deserve.
The lack of commision sales means that consumers are not going to talk to intelligent sales people who understand and know about the product. You may assume commision sales people might lie to get you to buy a certain product, while that certainly does happen, it is no different than talking to a non-com person at BB or CC. They are evaluated on the number of warranties, monster cables, etc etc they sell and if they want to keep their job, they better push more and more. Most commision sales people on the other hand belive in building relationships with customers so they will give sell them the products that will make the customer happy in the hopes that the customer will come back and buy from them again. Commision sales people are rewarded for hard work and good customer service in the form of higher pay. Non-Com people in retail are punished if they don't meet expectations. It is the whole attracting more flies with honey mentality at work. No CC or BB sales person cares enough about a customer to go the extra mile to help or try to get a manger to get them a better deal. Back in the day, when I worked commision retail sales, I always saw myself as an advocate of the customer in getting him the best deal instead of an instrument of the store in extracting the most money out of him. That kind of attitude inspired loyalty from my custoemrs.
Also, the low wages prevent anyone who has a clue from working at these stores due to the ability to make much more money elsewhere and CC and BB get the high school kids instead.
That is in a nutshell why you get the crappy service that you do. Is it great? Of course not, but it is a side effect of getting $40 of $200 coupons and great door buster prices. Retail stores know that in this day and age, if the in store prices are too high, people will just buy off the internet. The retail model is dying and i doubt we will see any retail electronic stores in 2020. A store like Walmart may still sell electronics in store, but the decicated retail electronics store is all but dead.